U.S. patent application number 10/091613 was filed with the patent office on 2002-11-28 for new ras-like protein.
This patent application is currently assigned to Incyte Pharmaceuticals, Inc.. Invention is credited to Corley, Neil C., Goli, Surya K., Hillman, Jennifer L..
Application Number | 20020177700 10/091613 |
Document ID | / |
Family ID | 25298956 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020177700 |
Kind Code |
A1 |
Hillman, Jennifer L. ; et
al. |
November 28, 2002 |
New ras-like protein
Abstract
The present invention provides a human Ras-like protein (RLP)
and polynucleotides which identify and encode RLP. The invention
also provides expression vectors, host cells, agonists, antibodies
and antagonists. In addition, the invention provides methods for
producing RLP and for treating or preventing disorders associated
with expression of RLP.
Inventors: |
Hillman, Jennifer L.; (San
Jose, CA) ; Goli, Surya K.; (Sunnyvale, CA) ;
Corley, Neil C.; (Mountain View, CA) |
Correspondence
Address: |
INCYTE GENOMICS, INC.
PATENT DEPARTMENT
3160 Porter Drive
Palo Alto
CA
94304
US
|
Assignee: |
Incyte Pharmaceuticals,
Inc.
|
Family ID: |
25298956 |
Appl. No.: |
10/091613 |
Filed: |
March 4, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10091613 |
Mar 4, 2002 |
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09198559 |
Nov 23, 1998 |
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09198559 |
Nov 23, 1998 |
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08846790 |
Apr 30, 1997 |
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5973130 |
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Current U.S.
Class: |
536/23.2 ;
435/193; 435/252.3; 435/320.1; 435/325; 435/69.1; 800/8 |
Current CPC
Class: |
A61K 38/00 20130101;
C07K 14/82 20130101 |
Class at
Publication: |
536/23.2 ;
435/69.1; 435/193; 435/320.1; 435/325; 800/8; 435/252.3 |
International
Class: |
A01K 067/00; C07H
021/04; C12N 009/10; C12P 021/02; C12N 005/06; C12N 001/21 |
Claims
What is claimed is:
1. An isolated polypeptide selected from the group consisting of:
a) a polypeptide comprising an amino acid sequence of SEQ ID NO:1,
b) a polypeptide comprising a naturally occurring amino acid
sequence at least 90% identical to an amino acid sequence of SEQ ID
NO:1, c) a biologically active fragment of a polypeptide having an
amino acid sequence of SEQ ID NO:l, and d) an immunogenic fragment
of a polypeptide having an amino acid sequence of SEQ ID NO:1.
2. An isolated polypeptide of claim 1 comprising an amino acid
sequence of SEQ ID NO:1.
3. An isolated polynucleotide encoding a polypeptide of claim
1.
4. An isolated polynucleotide encoding a polypeptide of claim
2.
5. An isolated polynucleotide of claim 4 comprising a
polynucleotide sequence of SEQ ID NO:2.
6. A recombinant polynucleotide comprising a promoter sequence
operably linked to a polynucleotide of claim 3.
7. A cell transformed with a recombinant polynucleotide of claim
6.
8. A transgenic organism comprising a recombinant polynucleotide of
claim 6.
9. A method of producing a polypeptide of claim 1, the method
comprising: a) culturing a cell under conditions suitable for
expression of the polypeptide, wherein said cell is transformed
with a recombinant polynucleotide, and said recombinant
polynucleotide comprises a promoter sequence operably linked to a
polynucleotide encoding the polypeptide of claim 1, and b)
recovering the polypeptide so expressed.
10. A method of claim 9, wherein the polypeptide comprises an amino
acid sequence of SEQ ID NO:1.
11. An isolated antibody which specifically binds to a polypeptide
of claim 1.
12. An isolated polynucleotide selected from the group consisting
of: a) a polynucleotide comprising a polynucleotide sequence of SEQ
ID NO:2, b) a polynucleotide comprising a naturally occurring
polynucleotide sequence at least 90% identical to a polynucleotide
sequence selected from the group consisting of SEQ ID NO:2, c) a
polynucleotide complementary to a polynucleotide of a), d) a
polynucleotide complementary to a polynucleotide of b), and e) an
RNA equivalent of a)-d).
13. An isolated polynucleotide comprising at least 60 contiguous
nucleotides of a polynucleotide of claim 12.
14. A method of detecting a target polynucleotide in a sample, said
target polynucleotide having a sequence of a polynucleotide of
claim 12, the method comprising: a) hybridizing the sample with a
probe comprising at least 20 contiguous nucleotides comprising a
sequence complementary to said target polynucleotide in the sample,
and which probe specifically hybridizes to said target
polynucleotide, under conditions whereby a hybridization complex is
formed between said probe and said target polynucleotide or
fragments thereof, and b) detecting the presence or absence of said
hybridization complex, and, optionally, if present, the amount
thereof.
15. A method of claim 14, wherein the probe comprises at least 60
contiguous nucleotides.
16. A method of detecting a target polynucleotide in a sample, said
target polynucleotide having a sequence of a polynucleotide of
claim 12, the method comprising: a) amplifying said target
polynucleotide or fragment thereof using polymerase chain reaction
amplification, and b) detecting the presence or absence of said
amplified target polynucleotide or fragment thereof, and,
optionally, if present, the amount thereof.
17. A composition comprising a polypeptide of claim 1 and a
pharmaceutically acceptable excipient.
18. A composition of claim 17, wherein the polypeptide comprises an
amino acid sequence of SEQ ID NO: 1.
19. A method for treating a disease or condition associated with
decreased expression of functional RLP, comprising administering to
a patient in need of such treatment the composition of claim
17.
20. A method of screening a compound for effectiveness as an
agonist of a polypeptide of claim 1, the method comprising: a)
exposing a sample comprising a polypeptide of claim 1 to a
compound, and b) detecting agonist activity in the sample.
21. A composition comprising an agonist compound identified by a
method of claim 20 and a pharmaceutically acceptable excipient.
22. A method for treating a disease or condition associated with
decreased expression of functional RLP, comprising administering to
a patient in need of such treatment a composition of claim 21.
23. A method of screening a compound for effectiveness as an
antagonist of a polypeptide of claim 1, the method comprising: a)
exposing a sample comprising a polypeptide of claim 1 to a
compound, and b) detecting antagonist activity in the sample.
24. A composition comprising an antagonist compound identified by a
method of claim 23 and a pharmaceutically acceptable excipient.
25. A method for treating a disease or condition associated with
overexpression of functional RLP, comprising administering to a
patient in need of such treatment a composition of claim 24.
26. A method of screening for a compound that specifically binds to
the polypeptide of claim 1, the method comprising: a) combi n ig
the polypeptide of claim 1 with at least one test compound under
suitable conditions, and b) detecting binding of the polypeptide of
claim 1 to the test compound, thereby identifying a compound that
specifically binds to the polypeptide of claim 1.
27. A method of screening for a compound that modulates the
activity of the polypeptide of claim 1, the method comprising: a)
combining the polypeptide of claim 1 with at least one test
compound under conditions per m issive for the activity of the
polypeptide of claim 1, b) assessing the activity of the
polypeptide of claim 1 in the presence of the test compound, and c)
comparing the activity of the polypeptide of claim 1 in the
presence of the test compound with the activity of the polypeptide
of claim 1 in the absence of the test compound, wherein a change in
the activity of the polypeptide of claim 1 in the presence of the
test compound is indicative of a compound that modulates the
activity of the polypeptide of claim 1.
28. A method of screening a compound for effectiveness in altering
expression of a target polynucleotide, wherein said target
polynucleotide comprises a sequence of claim 5, the method
comprising: a) exposing a sample comprising the target
polynucleotide to a compound, under conditions suitable for the
expression of the target polynucleotide, b) detecting altered
expression of the target polynucleotide, and c) comparing the
expression of the target polynucleotide in the presence of varying
amounts of the compound and in the absence of the compound.
29. A method of assessing toxicity of a test compound, the method
comprising: a) treating a biological sample containing nucleic
acids with the test compound, b) hybridizing the nucleic acids of
the treated biological sample with a probe comprising at least 20
contiguous nucleotides of a polynucleotide of claim 12 under
conditions whereby a specific hybridization complex is formed
between said probe and a target polynucleotide in the biological
sample, said target polynucleotide comprising a polynucleotide
sequence of a polynucleotide of claim 12 or fragment thereof, c)
quantifying the amount of hybridization complex, and d) comparing
the amount of hybridization complex in the treated biological
sample with the amount of hybridization complex in an untreated
biological sample, wherein a difference in the amount of
hybridization complex in the treated biological sample is
indicative of toxicity of the test compound.
30. A diagnostic test for a condition or disease associated with
the expression of RLP in a biological sample, the method
comprising: a) combining the biological sample with an antibody of
claim 11, under conditions suitable for the antibody to bind the
polypeptide and form an antibody:polypeptide complex, and b)
detecting the complex, wherein the presence of the complex
correlates with the presence of the polypeptide in the biological
sample.
31. The antibody of claim 11, wherein the antibody is: a) a
chimeric antibody, b) a single chain antibody, c) a Fab fragment,
d) a F(ab').sub.2fragment, or e) a humanized antibody.
32. A composition comprising an antibody of claim 11 and an
acceptable excipient.
33. A method of diagnosing a condition or disease associated with
the expression of RLP in a subject, comprising administering to
said subject an effective amount of the composition of claim
32.
34. A composition of claim 32, wherein the antibody is labeled.
35. A method of diagnosing a condition or disease associated with
the expression of RLP in a subject, comprising administering to
said subject an effective amount of the composition of claim
34.
36. A method of preparing a polyclonal antibody with the
specificity of the antibody of claim 11, the method comprising: a)
immunizing an animal with a polypeptide consisting of an amino acid
sequence of SEQ ID NO: 1, or an immunogenic fragment thereof, under
conditions to elicit an antibody response, b) isolating antibodies
from said animal, and c) screening the isolated antibodies with the
polypeptide, thereby identif y ig a polyclonal antibody which
specifically binds to a polypeptide comprising an amino acid
sequence of SEQ ID NO: 1.
37. A polyclonal antibody produced by a method of claim 36.
38. A composition comprising the polyclonal antibody of claim 37
and a suitable carrier.
39. A method of making a monoclonal antibody with the specificity
of the antibody of claim 11, the method comprising: a) immunizing
an animal with a polypeptide consisting of an amino acid sequence
of SEQ ID NO: 1, or an immunogenic fragment thereof, under
conditions to elicit an antibody response, b) isolating antibody
producing cells from the animal, c) fusing the antibody producing
cells with immortalized cells to form monoclonal antibody-producing
hybridoma cells, d) culturing the hybridoma cells, and e) isolating
from the culture monoclonal antibody which specifically binds to a
polypeptide comprising an amino acid sequence of SEQ ID NO: 1.
40. A monoclonal antibody produced by a method of claim 39.
41. A composition comprising the monoclonal antibody of claim 40
and a suitable carrier.
42. The antibody of claim 11, wherein the antibody is produced by
screening a Fab expression library.
43. The antibody of claim 11, wherein the antibody is produced by
screening a recombinant immunoglobulin library.
44. A method of detecting a polypeptide comprising an amino acid
sequence of SEQ ID NO:1 in a sample, the method comprising: a)
incubating the antibody of claim 11 with a sample under conditions
to allow specific binding of the antibody and the polypeptide, and
b) detecting specific binding, wherein specific binding indicates
the presence of a polypeptide comprising an amino acid sequence of
SEQ ID NO:1 in the sample.
45. A method of purifying a polypeptide comprising an amino acid
sequence of SEQ ID NO:1 from a sample, the method comprising: a)
incubating the antibody of claim 11 with a sample under conditions
to allow specific binding of the antibody and the polypeptide, and
b) separating the antibody from the sample and obtaining the
purified polypeptide comprising an amino acid sequence of SEQ ID
NO: I.
46. A microarray wherein at least one element of the microarray is
a polynucleotide of claim 13.
47. A method of generating an expression profile of a sample which
contains polynucleotides, the method comprising: a) labeling the
polynucleotides of the sample, b) contacting the elements of the
microarray of claim 46 with the labeled polynucleotides of the
sample under conditions suitable for the formation of a
hybridization complex, and c) quantifying the expression of the
polynucleotides in the sample.
48. An array comprising different nucleotide molecules affixed in
distinct physical locations on a solid substrate, wherein at least
one of said nucleotide molecules comprises a first oligonucleotide
or polynucleotide sequence specifically hybridizable with at least
30 contiguous nucleotides of a target polynucleotide, and wherein
said target polynucleotide is a polynucleotide of claim 12.
49. An array of claim 48, wherein said first oligonucleotide or
polynucleotide sequence is completely complementary to at least 30
contiguous nucleotides of said target polynucleotide.
50. An array of claim 48, wherein said first oligonucleotide or
polynucleotide sequence is completely complementary to at least 60
contiguous nucleotides of said target polynucleotide.
51. An array of claim 48, wherein said first oligonucleotide or
polynucleotide sequence is completely complementary to said target
polynucleotide.
52. An array of claim 48, which is a microarray.
53. An array of claim 48, further comprising said target
polynucleotide hybridized to a nucleotide molecule comprising said
first oligonucleotide or polynucleotide sequence.
54. An array of claim 48, wherein a linker joins at least one of
said nucleotide molecules to said solid substrate.
55. An array of claim 48, wherein each distinct physical location
on the substrate contains multiple nucleotide molecules, and the
multiple nucleotide molecules at any single distinct physical
location have the same sequence, and each distinct physical
location on the substrate contains nucleotide molecules having a
sequence which differs from the sequence of nucleotide molecules at
another distinct physical location on the substrate.
56. A polypeptide of claim 1, comprising the a tnino acid sequence
of SEQ ID NO: 1.
57. A polynucleotide of claim 12, comprising the polynucleotide
sequence of SEQ ID NO:2.
Description
[0001] This application is a continuation of co-pending U.S.
application Ser. No. 09/198,559, filed on Nov. 23, 1998, entitled
New Ras-like Protein, the disclosure of which is incorporated by
reference.
[0002] U.S. application Ser. No. 09/198,559 is a divisional of U.S.
application Ser. No. 08/846,790, filed on Apr. 30, 1997, now U.S.
Pat. No. 5,973,130, issued on Oct. 26, 1999, the disclosure of
which is incorporated by reference.
FIELD OF THE INVENTION
[0003] This invention relates to nucleic acid and amno acid
sequences of a new human Ras-like protein and to the use of these
sequences in the diagnosis, prevention, and treatment of disorders
associated with cell proliferation and inflammation.
BACKGROUND OF THE INVENTION
[0004] Guanine nucleotide-binding proteins (GTP-binding proteins,
or G proteins) participate in a wide range of regulatory functions
including metabolism, growth, differentiation, signal transduction,
cytoskeletal organization, and intracellular vesicle transport and
secretion. These proteins control a diverse sets of regulatory
pathways in response to hormones, growth factors, neuromodulators,
or other signaling molecules. When these molecules bind to
transmembrane receptors, signals are propagated to effector
molecules by intracellular signal transducing proteins. Many of
these signal transducing proteins are members of GTP-binding
proteins.
[0005] Low molecular weight (LMW) GTP-binding proteins are small
proteins which consist of single polypeptides of 21-30 kDa. These
proteins regulate cell growth, cell cycle control, protein
secretion, and intracellular vesicle interaction. In particular,
the LMW GTP-binding proteins activate cellular proteins by
transducing mitogenic signals involved in various cell functions in
response to extracellular signals from receptors (Tavitian, A.
(1995) C. R. Seances Soc. Biol. Fil. 189:7-12). During this
process, the hydrolysis of GTP acts as an energy source as well as
an on-off switch for the GTPase activity of the LMW GTP-binding
proteins.
[0006] The LMW GTP-binding proteins are classified into five
subfamilies: Ras, Rho, Ran, Rab, and ADP-ribosylation factor.
Despite their sequence variations, all five subfamilies share
common conserved structural features. Four sequence regions, termed
motifs I-IV, are conserved in the LMW GTP-binding proteins. Motif I
is the most variable and has the signature, GXXXXGK. The lysine
residue is essential in interacting with the .beta.- and
.gamma.-phosphates of GTP. Motif II, III, and IV are highly
conserved, with DTAGQE, NKXD, and EXSAX as their respective
signatures. These motifs regulate the binding of .gamma.-phosphate,
GTP, and the guanine base of GTP, respectively. Most of the
membrane bound LMW GTP-binding proteins generally require a carboxy
terminal isoprenyl group for membrane association and biological
activity. The isoprenyl group is added posttranslationally by a
mechanism which recognizes a terminal cysteine residue alone or a
terminal cysteine-aliphatic amino acid-aliphatic amino acid-any
amino acid (CAAX) motif. Additional membrane-binding energy is
often provided by either internal palmitoylation or a carboxy
terminal cluster of basic amino acids. The LMW GTP-binding proteins
also have a variable effector region, located between motifs I and
II, which is characterized as the interaction site for guanine
nucleotide exchange factors (GEFs) or GTPase activating proteins
(GAPs). GEFs induce the release of GDP from the active form of the
G protein, whereas GAPs interact with the inactive form by
stimulating the GTPase activity of the G protein.
[0007] The Ras subfaily proteins already indicated supra are
essential in transducing signals from receptor tyrosine kinases
(RTKs) to a series of serine/threonine kinases which control cell
growth and differentiation. Mutant Ras proteins, which bind but
cannot hydrolyze GTP, are permanently activated, and cause
continuous cell proliferation or cancer. TC21, a Ras-like protein,
is found to be highly expressed in a human teratocarcinoma cell
line (Drivas, G. T. et al. (1990) Mol. Cell. Biol. 10: 1793-1798).
Rin and Rit are characterized as membrane-binding, Ras-like
proteins without the lipid-binding CAAX motif and carboxy terminal
cysteine (Lee, C.-H. J. et al. (1996) J. Neurosci. 16: 6784-6794).
Further, Rin is shown to localize in neurons and have
calcium-dependant calmodulin-binding activity.
[0008] The discovery of a new human Ras-like protein and the
polynucleotides which encode it satisfies a need in the art by
providing new compositions which are useful in the diagnosis,
prevention, and treatment of disorders associated with cell
proliferation and inflammation.
SUMMARY OF THE INVENTION
[0009] The present invention features a human Ras-like protein
hereinafter designated RLP and characterized as having similarity
to a human and a mouse Ras-like protein, TC21 and Rit,
respectively.
[0010] Accordingly, the invention features a substantially purified
RLP having the amino acid sequence shown in SEQ ID NO: 1.
[0011] One aspect of the invention features isolated and
substantially purified polynucleotides that encode RLP. In a
particular aspect, the polynucleotide is the nucleotide sequence of
SEQ ID NO:2.
[0012] The invention also relates to a polynucleotide sequence
comprising the complement of SEQ ID NO:2 or variants thereof. In
addition, the invention features polynucleotide sequences which
hybridize under stringent conditions to SEQ ID NO:2.
[0013] The invention additionally features nucleic acid sequences
encoding fragments, or the complement of the polynucleotide
sequences, as well as expression vectors and host cells comprising
polynucleotides that encode RLP. The present invention also
features antibodies which bind specifically to RLP, and
pharmaceutical compositions comprising substantially purified RLP.
The invention also features methods for stimulating cell
proliferation using RLP, and for treating or preventing a disorder
associated with cell proliferation or inflammation using an
antagonist of RLP.
BRIEF DESCRIPTION OF THE FIGS.
[0014] Figures 1A, 1B, and 1C show the amino acid sequence (SEQ ID
NO: 1) and nucleic acid sequence (SEQ ID NO:2) of RLP. The
alignment was produced using MACDNASIS PRO software (Hitachi
Software Engineering Co., Ltd., San Bruno, Calif.).
[0015] FIG. 2 shows the amino acid sequence alignments among RLP
(SEQ ID NO: 1), a human Ras-like protein, TC21 (GI 190877; SEQ ID
NO:3), and a mouse Ras-like protein, Rit (GI 1656005; SEQ ID NO:4).
The alignment was produced using the multisequence alignment
program of DNASTAR software (DNASTAR Inc, Madison Wis.).
[0016] FIGS. 3A and 3B show the hydrophobicity plots (MACDNASIS PRO
software) for RLP (SEQ ID NO: 1) and the human Ras protein (SEQ ID
NO:3), respectively. The positive X axis reflects amino acid
position, and the negative Y axis, hydrophobicity.
DESCRIPTION OF THE INVENTION
[0017] Before the present proteins, nucleotide sequences, and
methods are described, it is understood that this invention is not
limited to the particular methodology, protocols, cell lines,
vectors, and reagents described as these may vary. It is also to be
understood that the terminology used herein is for the purpose of
describing particular embodiments only, and is not intended to
limit the scope of the present invention which will be limited only
by the appended claims.
[0018] It must be noted that as used herein and in the appended
claims, the singular forms "a", "an", and "the" include plural
reference unless the context clearly dictates otherwise. Thus, for
example, reference to "a host cell" includes a plurality of such
host cells, reference to the "antibody" is a reference to one or
more antibodies and equivalents thereof known to those skilled in
the art, and so forth.
[0019] Unless defined otherwise, all technical and scientific terms
used herein have the same meanings as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
any methods and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, the preferred methods, devices, and materials are now
described. All publications mentioned herein are incorporated
herein by reference for the purpose of describing and disclosing
the cell lines, vectors, and methodologies which are reported in
the publications which might be used in connection with the
invention. Nothing herein is to be construed as an admission that
the invention is not entitled to antedate such disclosure by virtue
of prior invention.
[0020] Definitions
[0021] "Nucleic acid sequence" as used herein refers to an
oligonucleotide, nucleotide, or polynucleotide, and fragments or
portions thereof, and to DNA or RNA of genomic or synthetic origin
which may be single- or double-stranded, and represent the sense or
antisense strand. Similarly, "amino acid sequence" as used herein
refers to an oligopeptide, peptide, polypeptide, or protein
sequence, and fragments or portions thereof, and to naturally
occurring or synthetic molecules.
[0022] Where "amino acid sequence" is recited herein to refer to an
amino acid sequence of a naturally occurring protein molecule,
"amino acid sequence" and like terms, such as "polypeptide" or
"protein" are not meant to limit the amino acid sequence to the
complete, native amino acid sequence associated with the recited
protein molecule.
[0023] "Peptide nucleic acid", as used herein, refers to a molecule
which comprises an oligomer to which an amino acid residue, such as
lysine, and an amino group have been added. These small molecules,
also designated anti-gene agents, stop transcript elongation by
binding to their complementary strand of nucleic acid (Nielsen, P.
E. et al. (1993) Anticancer Drug Des. 8:53-63).
[0024] "RLP", as used herein, refers to the amino acid sequences of
substantially purified RLP obtained from any species, particularly
mammalian, including bovine, ovine, porcine, murine, equine, and
preferably human, from any source whether natural, synthetic,
semi-synthetic, or recombinant.
[0025] "Consensus", as used herein, refers to a nucleic acid
sequence which has been resequenced to resolve uncalled bases, or
which has been extended using XL-PCR.TM. (Perkin Elmer, Norwalk,
Conn.) in the 5' and/or the 3' direction and resequenced, or which
has been assembled from the overlapping sequences of more than one
Incyte clone using the GELVIEW.TM. Fragment Assembly system (GCG,
Madison, Wis.), or which has been both extended and assembled.
[0026] A "variant" of RLP, as used herein, refers to an amino acid
sequence that is altered by one or more amino acids. The variant
may have "conservative" changes, wherein a substituted amino acid
has similar structural or chemical properties, e.g., replacement of
leucine with isoleucine. More rarely, a variant may have
"nonconservative" changes, e.g., replacement of a glycine with a
tryptophan. Similar minor variations may also include amino acid
deletions or insertions, or both. Guidance in determining which
amino acid residues may be substituted, inserted, or deleted
without abolishing biological or immunological activity may be
found using computer programs well known in the art, for example,
DNASTAR software.
[0027] A "deletion", as used herein, refers to a change in either
amino acid or nucleotide sequence in which one or more amino acid
or nucleotide residues, respectively, are absent.
[0028] An "insertion" or "addition", as used herein, refers to a
change in an amino acid or nucleotide sequence resulting in the
addition of one or more amino acid or nucleotide residues,
respectively, as compared to the naturally occurring molecule.
[0029] A "substitution", as used herein, refers to the replacement
of one or more amino acids or nucleotides by different amino acids
or nucleotides, respectively.
[0030] The term "biologically active", as used herein, refers to a
protein having structural, regulatory, or biochemical functions of
a naturally occurring molecule. Likewise, "immunologically active"
refers to the capability of the natural, recombinant, or synthetic
RLP, or any oligopeptide thereof, to induce a specific immune
response in appropriate animals or cells and to bind with specific
antibodies.
[0031] The term "agonist", as used herein, refers to a molecule
which, when bound to RLP, causes a change in RLP which modulates
the activity of RLP. Agonists may include proteins, nucleic acids,
carbohydrates, or any other molecules which bind to RLP.
[0032] The terms "antagonist" or "inhibitor", as used herein, refer
to a molecule which, when bound to RLP, blocks or modulates the
biological or immunological activity of RLP. Antagonists and
inhibitors may include proteins, nucleic acids, carbohydrates, or
any other molecules which bind to RLP.
[0033] The term "modulate", as used herein, refers to a change or
an alteration in the biological activity of RLP. Modulation may be
an increase or a decrease in protein activity, a change in binding
characteristics, or any other change in the biological, functional
or immunological properties of RLP.
[0034] The term "mimetic", as used herein, refers to a molecule,
the structure of which is developed from knowledge of the structure
of RLP or portions thereof and, as such, is able to effect some or
all of the actions of the Ras-like protein.
[0035] The term "derivative", as used herein, refers to the
chemical modification of a nucleic acid encoding RLP or the encoded
RLP. Illustrative of such modifications would be replacement of
hydrogen by an alkyl, acyl, or amino group. A nucleic acid
derivative would encode a polypeptide which retains essential
biological characteristics of the natural molecule.
[0036] The term "substantially purified", as used herein, refers to
nucleic or amino acid sequences that are removed from their natural
environment, isolated or separated, and are at least 60% free,
preferably 75% free, and most preferably 90% free from other
components with which they are naturally associated.
[0037] "Amplification" as used herein refers to the production of
additional copies of a nucleic acid sequence and is generally
carried out using polymerase chain reaction (PCR) technologies well
known in the art (Dieffenbach, C. W. and G. S. Dveksler (1995) PCR
Primer, a Laboratory Manual, Cold Spring Harbor Press, Plainview,
N.Y.).
[0038] The term "hybridization", as used herein, refers to any
process by which a strand of nucleic acid bonds with a
complementary strand through base pairing.
[0039] The term "hybridization complex", as used herein, refers to
a complex formed between two nucleic acid sequences by virtue of
the formation of hydrogen bonds between complementary G and C bases
and between complementary A and T bases; these hydrogen bonds may
be further stabilized by base stacking interactions. The two
complementary nucleic acid sequences hydrogen bond in an
antiparallel configuration. A hybridization complex may be formed
in solution (e.g., C.sub.0t or R.sub.0t analysis) or between one
nucleic acid sequence present in solution and another nucleic acid
sequence immobilized on a solid support (e.g., membranes, filters,
chips, pins or glass slides to which cells have been fixed for in
situ hybridization).
[0040] The terms "complementary" or "complementarity", as used
herein, refer to the natural binding of polynucleotides under
permissive salt and temperature conditions by base-pairing. For
example, the sequence "A-G-T" binds to the complementary sequence
"T-C-A". Complementarity between two single-stranded molecules may
be "partial", in which only some of the nucleic acids bind, or it
may be complete when total complementarity exists between the
single stranded molecules. The degree of complementarity between
nucleic acid strands has significant effects on the efficiency and
strength of hybridization between nucleic acid strands. This is of
particular importance in amplification reactions, which depend upon
binding between nucleic acids strands.
[0041] The term "homology", as used herein, refers to a degree of
complementarity. There may be partial homology or complete homology
(i.e., identity). A partially complementary sequence is one that at
least partially inhibits an identical sequence from hybridizing to
a target nucleic acid; it is referred to using the functional term
"substantially homologous." The inhibition of hybridization of the
completely complementary sequence to the target sequence may be
examined using a hybridization assay (Southern or northern blot,
solution hybridization and the like) under conditions of low
stringency. A substantially homologous sequence or probe will
compete for and inhibit the binding (i.e., the hybridization) of a
completely homologous sequence or probe to the target sequence
under conditions of low stringency. This is not to say that
conditions of low stringency are such that non-specific binding is
permitted; low stringency conditions require that the binding of
two sequences to one another be a specific (i.e., selective)
interaction. The absence of non-specific binding may be tested by
the use of a second target sequence which lacks even a partial
degree of complementarity (e.g., less than about 30% identity); in
the absence of non-specific binding, the probe will not hybridize
to the second non-complementary target sequence.
[0042] As known in the art, numerous equivalent conditions may be
employed to comprise either low or high stringency conditions.
Factors such as the length and nature (DNA, RNA, base composition)
of the sequence, nature of the target (DNA, RNA, base composition,
presence in solution or immobilization, etc.), and the
concentration of the salts and other components (e.g., the presence
or absence of formanide, dextran sulfate and/or polyethylene
glycol) are considered and the hybridization solution may be varied
to generate conditions of either low or high stringency different
from, but equivalent to, the above listed conditions.
[0043] The term "stringent conditions", as used herein, is the
"stringency" which occurs within a range from about Tm-5.degree. C.
(5.degree. C. below the melting temperature (Tm) of the probe) to
about 20.degree. C. to 25.degree. C. below Tm. As will be
understood by those of skill in the art, the stringency of
hybridization may be altered in order to identify or detect
identical or related polynucleotide sequences.
[0044] The term "antisense", as used herein, refers to nucleotide
sequences which are complementary to a specific DNA or RNA
sequence. The term "antisense strand" is used in reference to a
nucleic acid strand that is complementary to the "sense" strand.
Antisense molecules may be produced by any method, including
synthesis by ligating the gene(s) of interest in a reverse
orientation to a viral promoter which permits the synthesis of a
complementary strand. Once introduced into a cell, this transcribed
strand combines with natural sequences produced by the cell to form
duplexes. These duplexes then block either the further
transcription or translation. In this manner, mutant phenotypes may
be generated. The designation "negative" is sometimes used in
reference to the antisense strand, and "positive" is sometimes used
in reference to the sense strand.
[0045] The term "portion", as used herein, with regard to a protein
(as in "a portion of a given protein") refers to fragments of that
protein. The fragments may range in size from four amino acid
residues to the entire amino acid sequence minus one amino acid.
Thus, a protein "comprising at least a portion of the amino acid
sequence of SEQ ID NO:1" encompasses the full-length human RLP and
fragments thereof.
[0046] "Transformation", as defined herein, describes a process by
which exogenous DNA enters and changes a recipient cell. It may
occur under natural or artificial conditions using various methods
well known in the art. Transformation may rely on any known method
for the insertion of foreign nucleic acid sequences into a
prokaryotic or eukaryotic host cell. The method is selected based
on the host cell being transformed and may include, but is not
limited to, viral infection, electroporation, lipofection, and
particle bombardment. Such "transformed" cells include stably
transformed cells in which the inserted DNA is capable of
replication either as an autonomously replicating plasmid or as
part of the host chromosome. They also include cells which
transiently express the inserted DNA or RNA for limited periods of
time.
[0047] The term "antigenic determinant", as used herein, refers to
that portion of a molecule that makes contact with a particular
antibody (i.e., an epitope). When a protein or fragment of a
protein is used to immunize a host animal, numerous regions of the
protein may induce the production of antibodies which bind
specifically to a given region or three-dimensional structure on
the protein; these regions or structures are referred to as
antigenic determinants. An antigenic determinant may compete with
the intact antigen (i.e., the immunogen used to elicit the immune
response) for binding to an antibody.
[0048] The terms "specific binding" or "specifically binding", as
used herein, in reference to the interaction of an antibody and a
protein or peptide, mean that the interaction is dependent upon the
presence of a particular structure (i.e., the antigenic determinant
or epitope) on the protein; in other words, the antibody is
recognizing and binding to a specific protein structure rather than
to proteins in general. For example, if an antibody is specific for
epitope "A", the presence of a protein containing epitope A (or
free, unlabeled A) in a reaction containing labeled "A" and the
antibody will reduce the amount of labeled A bound to the
antibody.
[0049] The term "sample", as used herein, is used in its broadest
sense. A biological sample suspected of containing nucleic acid
encoding RLP or fragments thereof may comprise a cell, chromosomes
isolated from a cell (e.g., a spread of metaphase chromosomes),
genomic DNA (in solution or bound to a solid support such as for
Southern analysis), RNA (in solution or bound to a solid support
such as for northern analysis), cDNA (in solution or bound to a
solid support), an extract from cells or a tissue, and the
like.
[0050] The term "correlates with expression of a polynucleotide",
as used herein, indicates that the detection of the presence of
ribonucleic acid that is similar to SEQ ID NO:2 by northern
analysis is indicative of the presence of MRNA encoding RLP in a
sample and thereby correlates with expression of the transcript
from the polynucleotide encoding the protein.
[0051] "Alterations" in the polynucleotide of SEQ ID NO: 2, as used
herein, comprise any alteration in the sequence of polynucleotides
encoding RLP including deletions, insertions, and point mutations
that may be detected using hybridization assays. Included within
this definition is the detection of alterations to the genonic DNA
sequence which encodes RLP (e.g., by alterations in the pattern of
restriction fragment length polymorphisms capable of hybridizing to
SEQ ID NO:2), the inability of a selected fragment of SEQ ID NO: 2
to hybridize to a sample of genomic DNA (e.g., using
allele-specific oligonucleotide probes), and improper or unexpected
hybridization, such as hybridization to a locus other than the
normal chromosomal locus for the polynucleotide sequence encoding
RLP (e.g., using fluorescent in situ hybridization [FISH] to
metaphase chromosomes spreads).
[0052] As used herein, the term "antibody" refers to intact
molecules as well as fragments thereof, such as Fa, F(ab').sub.2,
and Fv, which are capable of binding the epitopic determinant.
Antibodies that bind RLP polypeptides can be prepared using intact
polypeptides or fragments containing small peptides of interest as
the immunizing antigen. The polypeptide or peptide used to immunize
an animal can be derived from the transition of RNA or synthesized
chemically, and can be conjugated to a carrier protein, if desired.
Commonly used carriers that are chemically coupled to peptides
include bovine serum albumin and thyroglobulin. The coupled peptide
is then used to immunize the animal (e.g., a mouse, a rat, or a
rabbit).
[0053] The term "humanized antibody", as used herein, refers to
antibody molecules in which amino acids have been replaced in the
non-antigen binding regions in order to more closely resemble a
human antibody, while still retaining the original binding
ability.
[0054] The Invention
[0055] The invention is based on the discovery of a new human
Ras-like protein (RLP), the polynucleotides encoding RLP, and the
use of these compositions for the diagnosis, prevention, or
treatment of disorders associated with cell proliferation and
inflammation.
[0056] Nucleic acids encoding the human RLP of the present
invention were first identified in Incyte Clone 683101 from an
uterine tissue cDNA library (UTRSNOT02) through a computer search
for amino acid sequence alignments. A consensus sequence, SEQ ID
NO:2, was derived from the following overlapping and/or extended
nucleic acid sequences: Incyte Clones 1282862 (COLNNOT16), 1501943
(SINTBST01), and 683101 (UTRSNOT02).
[0057] In one embodiment, the invention encompasses a polypeptide
comprising the amino acid sequence of SEQ ID NO: 1, as shown in
FIGS. 1A, 1B and 1C. RLP is 199 amino acids in length It has four
conserved GTP-binding sites encompassing residues G13-K19, D60-E65,
N118-D121, and E146-C150, which are analogous to those of other LMW
GTP-binding proteins. The effector binding region of RLP
encompasses residues D16-R24. Unlike most known members of the Ras
proteins, the carboxy terminus of RLP lacks either a CAAX motif or
a cysteine residue for lipid-binding. However, RLP has a carboxy
terminal cluster of basic residues and a potential EF-hand
calcium-binding domain encompassing residues D121-G133. These
features are similar to the Ras-like proteins, Rit (GI 1656005) and
Rin (Lee et al., supra), suggesting that RLP is a
membrane-associated protein with a potential calcium-dependent
function. Additionally, RLP has two potential N-glycosylation sites
at N110 and N155, two cAMP- and cGMP-dependent protein kinase
phosphorylation sites at R178-S181 and R179-S182, four potential
casein kinase II phosphorylation sites at T48-D51, S91E94,
S129-E132, and T189-E192, and four protein kinase C phosphorylation
sites at T28-R30, T42-R44, T87-R89, and T177-R179. As shown in FIG.
2, RLP has chemical and structural homology with a hurnan Ras-like
protein, TC21 (GI 190877; SEQ ID NO:3) and a mouse Ras-like
protein, Rit (GI 1656005; SEQ ID NO 4). In particular, RLP shares
47% identity with the Ras-like proteins, TC21 and Rit. As
illustrated by FIGS. 3A and 3B, RLP and TC21 have rather similar
hydrophobicity plots with the exception of their carboxy terminus.
Northern analysis shows the expression of RLP in various cDNA
libraries, at least 34% of which are immortalized or cancerous and
at least 67% of which either involve immune response or are
expressed in fetal/infant tissues or organs.
[0058] The invention also encompasses RLP variants. A preferred RLP
variant is one having at least 80%, and more preferably 90%, amino
acid sequence identity to the RLP amino acid sequence (SEQ ID NO:
1). A most preferred RLP variant is one having at least 95% amino
acid sequence identity to SEQ ID NO: 1.
[0059] The invention also encompasses polynucleotides which encode
RLP. Accordingly, any nucleic acid sequence which encodes the amino
acid sequence of RLP can be used to generate recombinant molecules
which express RLP. In a particular embodiment, the invention
encompasses the polynucleotide comprising the nucleic acid sequence
of SEQ ID NO:2 as shown in FIGS. 1A, 1B and 1C.
[0060] It will be appreciated by those skilled in the art that as a
result of the degeneracy of the genetic code, a multitude of
nucleotide sequences encoding RLP, some bearing minimal homology to
the nucleotide sequences of any known and naturally occurring gene,
may be produced. Thus, the invention contemplates each and every
possible variation of nucleotide sequence that could be made by
selecting combinations based on possible codon choices. These
combinations are made in accordance with the standard triplet
genetic code as applied to the nucleotide sequence of naturally
occurring RLP, and all such variations are to be considered as
being specifically disclosed.
[0061] Although nucleotide sequences which encode RLP and its
variants are preferably capable of hybridizing to the nucleotide
sequence of the naturally occurring RLP under appropriately
selected conditions of stringency, it may be advantageous to
produce nucleotide sequences encoding RLP or its derivatives
possessing a substantially different codon usage. Codons may be
selected to increase the rate at which expression of the peptide
occurs in a particular prokaryotic or eukaryotic host in accordance
with the frequency with which particular codons are utilized by the
host. Other reasons for substantially altering the nucleotide
sequence encoding RLP and its derivatives without altering the
encoded amino acid sequences include the production of RNA
transcripts having more desirable properties, such as a greater
half-life, than transcripts produced from the naturally occurring
sequence.
[0062] The invention also encompasses production of DNA sequences,
or portions thereof, which encode RLP and its derivatives, entirely
by synthetic chemistry. After production, the synthetic sequence
may be inserted into any of the many available expression vectors
and cell systems using reagents that are well known in the art at
the time of the filing of this application. Moreover, synthetic
chemistry may be used to introduce mutations into a sequence
encoding RLP or any portion thereof.
[0063] Also encompassed by the invention are polynucleotide
sequences that are capable of hybridizing to the claimed nucleotide
sequences, and in particular, those shown in SEQ ID NO:2, under
various conditions of stringency. Hybridization conditions are
based on the melting temperature (Tm) of the nucleic acid binding
conplex or probe, as taught in Wal, G. M. and S. L. Berger (1987;
Methods Enzymol. 152:399-407) and Kimmel, A. R. (1987; Methods
Enzymol. 152:507-511), and may be used at a defined stringency.
[0064] Altered nucleic acid sequences encoding RLP which are
encompassed by the invention include deletions, insertions, or
substitutions of different nucleotides resulting in a
polynucleotide that encodes the same or a functionally equivalent
RLP. The encoded protein may also contain deletions, insertions, or
substitutions of amino acid residues which produce a silent change
and result in a functionally equivalent RLP. Deliberate amino acid
substitutions may be made on the basis of similarity in polarity,
charge, solubility, hydrophobicity, hydrophilicity, and/or the
amphipathic nature of the residues as long as the biological
activity of RLP is retained. For example, negatively charged amino
acids may include aspartic acid and glutamic acid; positively
charged amino acids may include lysine and arginine; and amino
acids with uncharged polar head groups having similar
hydrophilicity values may include leucine, isoleucine, and valine;
glycine and alanine; asparagine and glutamine; serine and
threonine; phenylalanine and tyro sine.
[0065] Also included within the scope of the present invention are
alleles of the genes encoding RLP. As used herein, an "allele" or
"allelic sequence" is an alternative form of the gene which may
result from at least one mutation in the nucleic acid sequence.
Alleles may result in altered mRNAs or polypeptides whose structure
or function may or may not be altered. Any given gene may have
none, one, or many allelic forms. Common mutational changes which
give rise to alleles are generally ascribed to natural deletions,
additions, or substitutions of nucleotides. Each of these types of
changes may occur alone, or in combination with the others, one or
more times in a given sequence.
[0066] Methods for DNA sequencing which are well known and
generally available in the art may be used to practice any
embodiments of the invention. The methods may enploy such enzymes
as the Klenow fragment of DNA polymerase I, SEQUENASE (US
Biochemical Corp, Cleveland, OH), Taq polymerase (Perkin Elmer),
thermostable T7 polymerase (Amersham, Chicago, Ill.), or
combinations of recombinant polymerases and proofreading
exonucleases such as the ELONGASE Amplification System marketed by
Gibco BRL (Gaithersburg, Md.). Preferably, the process is automated
with machines such as the Ha m ilton Micro Lab 2200 (Harmilton,
Reno, Nev.), Peltier Thermal Cycler (PTC200; MJ Research,
Watertown, Mass.) and the ABI 377 DNA sequencers (Perkin
Elmer).
[0067] The nucleic acid sequences encoding RLP may be extended
utilizing a partial nucleotide sequence and employing various
methods known in the art to detect upstream sequences such as
promoters and regulatory elements. For example, one method which
may be employed, "restriction-site" PCR, uses universal primers to
retrieve unknown sequence adjacent to a known locus (Sarkar, G.
(1993) PCR Methods Applic. 2:318-322). In particular, genomic DNA
is first amplified in the presence of primer to linker sequence and
a primer specific to the known region. The amplified sequences are
then subjected to a second round of PCR with the same linker primer
and another specific primer internal to the first one. Products of
each round of PCR are transcribed with an appropriate RNA
polymerase and sequenced using reverse transcriptase.
[0068] Inverse PCR may also be used to amplify or extend sequences
using divergent primers based on a known region (Triglia, T. et al.
(1988) Nucleic Acids Res. 16:8186). The primers may be designed
using OLIGO 4.06 Primer Analysis software (National Biosciences
Inc., Plymouth, Minn.), or another appropriate program, to be 22-30
nucleotides in length, to have a GC content of 50% or more, and to
anneal to the target sequence at temperatures about
68.degree.-72.degree. C. The method uses several restriction
enzymes to generate a suitable fragment in the known region of a
gene. The fragment is then circularized by intramolecular ligation
and used as a PCR template.
[0069] Another method which may be used is capture PCR which
involves PCR amplification of DNA fragments adjacent to a known
sequence in human and yeast artificial chromosome DNA (Lagerstrom,
M. et al. (1991) PCR Methods Applic. 1:111-119). In this method,
multiple restriction enzyme digestions and ligations may also be
used to place an engineered double-stranded sequence into an
unknown portion of the DNA molecule before performing PCR.
[0070] Another method which may be used to retrieve unknown
sequences is that of Parker, J. D. et al. (1991; Nucleic Acids Res.
19:3055-3060). Additionally, one may use PCR, nested primers, and
PROMOTERFINDER libraries to walk in genomic DNA (Clontech, Palo
Alto, Calif.). This process avoids the need to screen libraries and
is useful in finding intron/exon junctions.
[0071] When screening for full-length cDNAs, it is preferable to
use libraries that have been size-selected to include larger cDNAs.
Also, random-primed libraries are preferable, in that they will
contain more sequences which contain the 5' regions of genes. Use
of a randomly primed library may be especially preferable for
situations in which an oligo d(T) library does not yield a
full-length cDNA.
[0072] Geno mnic libraries may be useful for extension of sequence
into the 5' and 3' non-transcribed regulatory regions.
[0073] Capillary electrophoresis systems which are commercially
available may be used to analyze the size or confirm the nucleotide
sequence of sequencing or PCR products. In particular, capillary
sequencing may employ flowable polymers for electrophoretic
separation, four different fluorescent dyes (one for each
nucleotide) which are laser activated, and detection of the emitted
wavelengths by a charge coupled deviCe camera. Output/light
intensity may be converted to electrical signal using appropriate
software (e.g. GENOTYPER and SEQUENCE NAVIGATOR, Perkin Elmer) and
the entire process from loading of samples to computer analysis and
electronic data display may be computer controlled. Capillary
electrophoresis is especially preferable for the sequencing of
small pieces of DNA which might be present in limited amounts in a
particular sample.
[0074] In another embodiment of the invention, polynucleotide
sequences or fragments thereof which encode RLP, or fusion proteins
or functional equivalents thereof, may be used in recombinant DNA
molecules to direct expression of RLP in appropriate host cells.
Due to the inherent degeneracy of the genetic code, other DNA
sequences which encode substantially the same or a functionally
equivalent amino acid sequence may be produced and these sequences
may be used to clone and express RLP. As will be understood by
those of skill in the art, it may be advantageous to produce
RLP-encoding nucleotide sequences possessing non-naturally
occurring codons. For example, codons preferred by a particular
prokaryotic or eukaryotic host can be selected to increase the rate
of protein expression or to produce a recombinant RNA transcript
having desirable properties, such as a half-life which is longer
than that of a transcript generated from the naturally occurring
sequence.
[0075] The nucleotide sequences of the present invention can be
engineered using methods generally known in the art in order to
alter RLP encoding sequences for a variety of reasons, including
but not limited to, alterations which modify the cloning,
processing, and/or expression of the gene product. DNA shuffling by
random fragmentation and PCR reassembly of gene fragments and
synthetic oligonucleotides may be used to engineer the nucleotide
sequences. For example, site-directed mutagenesis may be used to
insert new restriction sites, alter glycosylation patterns, change
codon preference, produce splice variants, or introduce mutations,
and so forth
[0076] In another embodiment of the invention, natural, modified,
or recombinant nucleic acid sequences encoding RLP may be ligated
to a heterologous sequence to encode a fusion protein. For example,
to screen peptide libraries for inhibitors of RLP activity, it may
be useful to encode a chimeric RLP protein that can be recognized
by a commercially available antibody. A fusion protein may also be
engineered to contain a cleavage site located between the RLP
encoding sequence and the heterologous protein sequence, so that
RLP may be cleaved and purified away from the heterologous
moiety.
[0077] In another embodiment, sequences encoding RLP may be
synthesized, in whole or in part, using chemical methods well known
in the art (see Caruthers, M. H. et al. (1980) Nucl. Acids Res.
[0078] Symp. Ser. 215-223, Hom, T. et al. (1980) Nucl. Acids Res.
Symp. Ser. 225-232). Alternatively, the protein itself may be
produced using chemical methods to synthesize the amino acid
sequence of RLP, or a portion thereof. For example, peptide
synthesis can be performed using various solid-phase techniques
(Roberge, J. Y. et al. (1995) Science 269:202-204) and automated
synthesis may be achieved, for example, using the ABI 431A Peptide
Synthesizer (Perkin Elmer).
[0079] The newly synthesized peptide may be substantially purified
by preparative high performance liquid chromatography (e.g.,
Creighton, T. (1983) Proteins, Structures and Molecular Principles,
W H Freeman and Co., New York, N.Y.). The composition of the
synthetic peptides may be confirmed by amino acid analysis or
sequencing (e.g., the Edman degradation procedure; Creighton,
supra). Additionally, the amino acid sequence of RLP, or any part
thereof, may be altered during direct synthesis and/or combined
using chemical methods with sequences from other proteins, or any
part thereof, to produce a variant polypeptide.
[0080] In order to express a biologically active RLP, the
nucleotide sequences encoding RLP or functional equivalents, may be
inserted into appropriate expression vector, i.e., a vector which
contains the necessary elements for the transcription and
translation of the inserted coding sequence.
[0081] Methods which are well known to those skilled in the art may
be used to construct expression vectors containing sequences
encoding RLP and appropriate transcriptional and translational
control elements. These methods include in vitro recombinant DNA
techniques, synthetic techniques, and in vivo genetic
recombination. Such techniques are described in Sambrook, J. et al.
(1989) Molecular Cloning, A Laboratory Manual, Cold Spring Harbor
Press, Plainview, N.Y., and Ausubel, F. M. et al. (1989) Current
Protocols in Molecular Biology, John Wiley & Sons, New York,
N.Y.
[0082] A variety of expression vector/host systems may be utilized
to contain and express sequences encoding RLP. These include, but
are not limited to, microorganisms such as bacteria transformed
with recombinant bacteriophage, plasmid, or cosmid DNA expression
vectors; yeast transformed with yeast expression vectors; insect
cell systems infected with virus expression vectors (e.g.,
baculovirus); plant cell systems transformed with virus expression
vectors (e.g., cauliflower mosaic virus, CaMV; tobacco mosaic
virus, TMV) or with bacterial expression vectors (e.g., Ti or
pBR322 plasmids); or animal cell systems.
[0083] The "control elements" or "regulatory sequences" are those
non-translated regions of the vector--enhancers, promoters, 5' and
3' untranslated regions--which interact with host cellular proteins
to carry out transcription and translation. Such elements may vary
in their strength and specificity. Depending on the vector system
and host utilized, any number of suitable transcription and
translation elements, including constitutive and inducible
promoters, may be used. For example, when cloning in bacterial
systems, inducible promoters such as the hybrid lacZ promoter of
the BLUESCRIPT phagemid (Stratagene, LaJolla, Calif.) or PSPORT1
plasmid (Gibco BRL) and the like may be used. The baculovirus
polyhedrin promoter may be used in insect cells. Promoters or
enhancers derived from the genomes of plant cells (e.g., heat
shock, RUBISCO; and storage protein genes) or from plant viruses
(e.g., viral promoters or leader sequences) may be cloned into the
vector. In ma mimalian cell systems, promoters from mammalian genes
or from mammalian viruses are preferable. If it is necessary to
generate a cell line that contains multiple copies of the sequence
encoding RLP, vectors based on SV40 or EBV may be used with an
appropriate selectable marker.
[0084] In bacterial systems, a number of expression vectors may be
selected depending upon the use intended for RLP. For example, when
large quantities of RLP are needed for the induction of antibodies,
vectors which direct high level expression of fusion proteins that
are readily purified may be used. Such vectors include, but are not
limited to, the multifunctional E. coli cloning and expression
vectors such as the BLUESCRIPT phagemid (Stratagene), in which the
sequence encoding RLP may be ligated into the vector in frame with
sequences for the a mino-te rminal Met and the subsequent 7
residues of B-galactosidase so that a hybrid protein is produced;
pIN vectors (Van Heeke, G. and S. M. Schuster (1989) J. Biol. Cheim
264:5503-5509); and the like. pGEX vectors (Promega, Madison, Wis.)
may also be used to express foreign polypeptides as fusion proteins
with glutathione S-transferase (GST). In general, such fusion
proteins are soluble and can easily be purified from lysed cells by
adsorption to glutathione-agarose beads followed by elution in the
presence of free glutathione. Proteins made in such systems may be
designed to include heparin, thrombin, or factor XA protease
cleavage sites so that the cloned polypeptide of interest can be
released from the GST moiety at will.
[0085] In the yeast, Saccharomyces cerevisiae, a number of vectors
containing constitutive or inducible promoters such as alpha
factor, alcohol oxidase, and PGH may be used. For reviews, see
Ausubel et al. (supra) and Grant et al. (1987) Methods Enzymol.
153:516-544.
[0086] In cases where plant expression vectors are used, the
expression of sequences encoding RLP may be driven by any of a
number of promoters. For example, viral promoters such as the 35S
and 19S promoters of CaMV may be used alone or in combination with
the omega leader sequence from TMV (Takamatsu, N. (1987) EMBO J.
6:307-311). Alternatively, plant promoters such as the small
subunit of RUBISCO or heat shock promoters may be used (Coruzzi, G.
et al. (1984) EMBO J. 3:1671-1680; Broglie, R. et al. (1984)
Science 224:838-843; and Winter, J. et al. (1991) Results Probl.
Cell Differ. 17:85-105). These constructs can be introduced into
plant cells by direct DNA transformation or pathogen-mediated
transfection. Such techniques are described in a nurnber of
generally available reviews (see, for example, Hobbs, S. or Murry,
L. E. in McGraw Hill Yearbook of Science and Technology (1992)
McGraw Hill, New York, N.Y.; pp. 191-196).
[0087] An insect system may also be used to express RLP. For
example, in one such system, Autographa californica nuclear
polyhedrosis virus (AcNPV) is used as a vector to express foreign
genes in Spodoptera frugiperda cells or in Trichoplusia larvae. The
sequences encoding RLP may be cloned into a non-essential region of
the virus, such as the polyhedrin gene, and placed under control of
the polyhedrin promoter. Successful insertion of RLP will render
the polyhedrin gene inactive and produce recombinant virus lacking
coat protein. The recombinant viruses may then be used to infect,
for example, S. frugiperda cells or Trichoplusia larvae in which
RLP may be expressed (Engelhard, E. K et al. (1994) Proc. Nat.
Acad. Sci. 91:3224-3227).
[0088] In mamalian host cells, a number of viral-based expression
systems may be utilized. In cases where an adenovirus is used as an
expression vector, sequences encoding RLP may be ligated into an
adenovirus transcription/translation complex consisting of the late
promoter and tripartite leader sequence. Insertion in a
non-essential E1 or E3 region of the viral genome may be used to
obtain a viable virus which is capable of expressing RLP in
infected host cells (Logan, J. and Shenk, T. (1984) Proc. Natl.
Acad. Sci. 81:3655-3659). In addition, transcription enhancers,
such as the Rous sarcoma virus (RSV) enhancer, may be used to
increase expression in mamalian host cells.
[0089] Specific initiation signals may also be used to achieve more
efficient translation of sequences encoding RLP. Such signals
include the ATG initiation codon and adjacent sequences. In cases
where sequences encoding RLP, its initiation codon, and upstream
sequences are inserted into the appropriate expression vector, no
additional transcriptional or translational control signals may be
needed. However, in cases where only coding sequence, or a portion
thereof, is inserted, exogenous translational control signals
including the ATG initiation codon should be provided. Furthermore,
the initiation codon should be in the correct reading frame to
ensure translation of the entire insert. Exogenous translational
elements and initiation codons may be of various origins, both
natural and synthetic. The efficiency of expression may be enhanced
by the inclusion of enhancers which are appropriate for the
particular cell system which is used, such as those described in
the literature (Scharf, D. et a]. (1994) Results Probl. Cell
Differ. 20:125-162).
[0090] In addition, a host cell strain may be chosen for its
ability to modulate the expression of the inserted sequences or to
process the expressed protein in the desired fashion. Such
modifications of the polypeptide include, but are not li mited to,
acetylation, carboxylation, glycosylation, phosphorylation,
lipidation, and acylation. Post-translational processing which
cleaves a "prepro" form of the protein may also be used to
facilitate correct insertion, folding and/or function. Different
host cells such as CHO, HeLa, MDCK, HEK293, and W138, which have
specific cellular machinery and characteristic mechanisms for such
post-translational activities, may be chosen to ensure the correct
modification and processing of the foreign protein.
[0091] For long-term, high-yield production of recombinant
proteins, stable expression is preferred. For example, cell lines
which stably express RLP may be transformed using expression
vectors which may contain viral origins of replication and/or
endogenous expression elements and a selectable marker gene on the
same or on a separate vector. Following the introduction of the
vector, cells may be allowed to grow for 1-2 days in an enriched
media before they are switched to selective media. The purpose of
the selectable marker is to confer resistance to selection, and its
presence allows growth and recovery of cells which successfully
express the introduced sequences. Resistant clones of stably
transformed cells may be proliferated using tissue culture
techniques appropriate to the cell type.
[0092] Any number of selection systems m may be used to recover
transformed cell lines. These include, but are not limited to, the
herpes simplex virus thymidine kinase (Wigler, M. et al. (1977)
Cell 11:223-32) and adenine phosphoribosyltransferase (Lowy, I. et
al. (1980) Cell 22:817-23) genes which can be employed in
tk.sup.-or aprt.sup.-cells, respectively. Also, antimetabolite,
antibiotic or herbicide resistance can be used as the basis for
selection; for example, dhfr which confers resistance to
methotrexate (Wigler, M. et al. (1980) Proc. Natl. Acad - Sci.
77:3567-70); npt, which confers resistance to the aminoglycosides
neomycin and G-418 (Colbere-Garapin, F. et al (1981) J. Mol. Biol.
150:1-14) and als or pat, which confer resistance to c blorsulfuron
and phosphinotricin acetyltransferase, respectively (Murry, supra).
Additional selectable genes have been described, for example,
trp.beta., which allows cells to utilize in dole in place of
tryptophan, or hisD, which allows cells to utilize histinol in
place of histidine (Hartman, S. C. and R. C. Mulligan (1988) Proc.
Natl. Acad. Sci. 85:8047-51). Recently, the use of visible markers
has gained popularity with such markers as anthocyanins, .beta.
glucuronidase and its substrate GUS, and luciferase and its
substrate luciferin, being widely used not only to identify
transformants, but also to quantify the amount of transient or
stable protein expression attributable to a specific vector system
(Rhodes, C. A. et al. (1995) Methods Mol. 20 Biol. 55:121-131).
[0093] Although the presence/absence of marker gene expression
suggests that the gene of interest is also present, its presence
and expression may need to be confirmed. For example, if the
sequence encoding RLP is inserted within a marker gene sequence,
recombinant cells containing sequences encoding RLP can be
identified by the absence of marker gene function. Alternatively, a
marker gene can be placed in tandem with a sequence encoding RLP
under the control of a single promoter. Expression of the marker
gene in response to induction or selection usually indicates
expression of the tandem gene as well.
[0094] Alternatively, host cells which contain the nucleic acid
sequence encoding RLP and express RLP may be identified by a
variety of procedures known to those of skill in the art. These
procedures include, but are not l i mited to, DNA-DNA or DNA-RNA
hybridizations and protein bioassay or immunoassay techniques which
include membrane, solution, or chip based technologies for the
detection and/or quantification of nucleic acid or protein.
[0095] The presence of polynucleotide sequences encoding RLP can be
detected by DNA-DNA or DNA-RNA hybridization or amplification using
probes or portions or fragments of polynucleotides encoding RLP.
Nucleic acid amplification based assays involve the use of
oligonucleotides or oligomers based on the sequences encoding RLP
to detect transformants containing DNA or RNA encoding RLP. As used
herein "oligonucleotides" or "oligomers" refer to a nucleic acid
sequence of at least about 10 nucleotides and as many as about 60
nucleotides, preferably about 15 to 30 nucleotides, and more
preferably about 20-25 nucleotides, which can be used as a probe or
amplimer.
[0096] A variety of protocols for detecting and measuring the
expression of RLP, using either polyclonal or monoclonal antibodies
specific for the protein are known in the art. Examples include
enzyme-linked irn munosorbent assay (ELISA), radioim munoassay
(RIA), and fluorescence activated cell sorting (FACS). A two-site,
monoclonal-based inununoassay utilizing monoclonal antibodies
reactive to two non-interfering epitopes on RLP is preferred, but a
competitive binding assay may be employed. These and other assays
are described, among other places, in Hampton, R. et al. (1990;
Serological Methods, a Laboratory Manual, APS Press, St Paul,
Minn.) and Maddox, D. E. et al. (1983;
[0097] J. Exp. Med. 158:1211-1216).
[0098] A wide variety of labels and conjugation techniques are
known by those skilled in the art and may be used in various
nucleic acid and amino acid assays. Means for producing labeled
hybridization or PCR probes for detecting sequences related to
polynucleotides encoding RLP include oligolabeling, nick
translation, end-labeling or PCR amplification using a labeled
nucleotide. Alternatively, the sequences encoding RLP, or any
portions thereof may be cloned into a vector for the production of
an MRNA probe. Such vectors are known in the art, are commercially
available, and may be used to synthesize RNA probes in vitro by
addition of an appropriate RNA polymerase such as T7, T3, or SP6
and labeled nucleotides. These procedures may be conducted using a
variety of commercially available kits (Pharmacia & Upjohn,
(Kalamazoo, Mich.); Promega (Madison Wis.); and U.S. Biochemical
Corp. (Cleveland, Ohio)). Suitable reporter molecules or labels,
which may be used, include radionuclides, enzymes, fluorescent,
chemiluminescent, or chromogenic agents as well as substrates,
cofactors, inhibitors, magnetic particles, and the like.
[0099] Host cells transformed with nucleotide sequences encoding
RLP may be cultured under conditions suitable for the expression
and recovery of the protein from cell culture. The protein produced
by a recombinant cell may be secreted or contained intracellularly
depending on the sequence and/or the vector used. As will be
understood by those of skill in the art, expression vectors
containing polynucleotides which encode RLP may be designed to
contain signal sequences which direct secretion of RLP through a
prokaryotic or eukaryotic cell membrane. Other recombinant
constructions may be used to join sequences encoding RLP to
nucleotide sequence encoding a polypeptide domain which will
facilitate purification of soluble proteins. Such purification
facilitating domains include, but are not limited to, metal
chelating peptides such as histidine-tryptophan modules that allow
purification on immobilized metals, protein A domains that allow
purification on immobilized immunoglobulin, and the domain utilized
in the FLAGS extension/affinity purification system (Immunex Corp.,
Seattle, Wash.). The inclusion of cleavable linker sequences such
as those specific for Factor XA or enterokinase (Invitrogen, San
Diego, Calif.) between the purification domain and RLP may be used
to facilitate purification. One such expression vector provides for
expression of a fusion protein containing RLP and a nucleic acid
encoding 6 histidine residues preceding a thioredoxin or an
enterokinase cleavage site. The histidine residues facilitate
purification on IMIAC (immobilized metal ion affinity
chromatography) as described in Porath, J. et al. (1992, Prot. Exp.
Purif. 3: 263-281) while the enterokinase cleavage site provides a
means for purifying RILP from the fusion protein. A discussion of
vectors which contain fusion proteins is provided in Kroll, D.J. et
al. (1993; DNA Cell Biol. 12:441-453).
[0100] In addition to recombinant production, fragments of RLP may
be produced by direct peptide synthesis using solid-phase
techniques (Merrifield J. (1963) J. Aim Che im Soc. 85:2149-2154).
Protein synthesis may be performed using manual techniques or by
automation. Automated synthesis may be achieved, for example ,
using Applied Biosystems 431A Peptide Synthesizer (Perkin Elmer).
Various fragments of RLP may be chemically synthesized separately
and combined using chemical methods to produce the full length
molecule.
[0101] Therapeutics
[0102] RLP shares chemical and structural homology with a human
Ras-like protein, TC21 (GI 190877) and a mouse Ras-like protein,
Rit (GI 1656005). Northern analysis shows that the expression of
RLP is associated with cell proliferation and inflammation am .
[0103] Therefore, in one embodiment, RLP or a fragment or
derivative thereof may be added to cells to stimulate cell
proliferation. In particular, RLP may be added to a cell or cells
in vivo using delivery mechanisms such as liposomes, viral based
vectors, or electroinjection for the purpose of promoting
regeneration or differentiation of the cell or cells. In addition,
RLP may be added to a cell, cell line, tissue or organ culture in
vitro or ex vivo to stimulate cell proliferation for use in
heterologous or autologous transplantation. In some cases, the cell
will have been selected for its ability to fight an infection or a
cancer or to correct a genetic defect in a disease such as sickle
cell anemia, D thalassemia, cystic fibrosis, or Huntington's
choria.
[0104] In another embodiment, an agonist which is specific for RLP
may be administered to stimulate cell proliferation, as detailed
above.
[0105] In still another embodiment, a vector capable of expressing
RLP, or a fragment or a derivative thereof, may be administered to
stimulate cell proliferation, as detailed above.
[0106] In another embodiment, an antagonist or an inhibitor of RLP,
or a fragment or a derivative thereof, may be ad ministered to a
subject to prevent or treat a disorder associated with cell
proliferation. Disorders of cell proliferation include various
types of cancer including, but not limited to, adenocarcinoma,
sarcoma, lymphoma, leukemia, melanoma, myeloma, teratocarcinoma,
and in particular, cancers of the bladder, bone, brain, breast,
gastrointestinal tract, heart, kidney, liver, lung, ovary,
pancreas, paraganglia, parathyroid, prostate, skin, testis,
thyroid, and uterus. In one aspect, an antibody specific for RLP
may be used directly as an antagonist, or indirectly as a targeting
or delivery mechanism for bringing a pharmaceutical agent to cells
or tissue which express RLP.
[0107] In still another embodiment, a vector expressing the
complementary sequence or antisense of the polynucleotide encoding
RLP, or a fragment or a derivative thereof, may be administered to
a subject to prevent or treat a disorder associated with cell
proliferation including, but not limited to, those listed
above.
[0108] In a further embodiment, an antagonist or an inhibitor of
RLP or a fragment or a derivative thereof, may be administered to a
subject to prevent or treat inflammation of any type and, in
particular, that which results from a particular disorder. Such
disorders of infla m mation include, but are not limited to, AIDS,
Addison's disease, allergies, asthma, bronchitis, Crohn's disease,
dermatomyositis, diabetes mellitus, emphysema, Graves' disease,
irritable bowel syndrome, lupus erythematosus, myasthenia gravis,
multiple sclerosis, urethritis, rheumatoid and osteoarthritis,
thyroiditis, and ulcerative colitis. In one aspect, an antibody
specific for RLP may be used directly as an antagonist, or
indirectly as a targeting or delivery mechanism for bringing a
pharmaceutical agent to cells or tissue which express RLP.
[0109] In another further embodiment, a vector expressing the
complementary sequence or antisense of the polynucleotide encoding
RLP, or a fragment or a derivative thereof, may be administered to
a subject to prevent or treat inflammation of any type including,
but not limited to, those listed above.
[0110] In other embodiments, any of the therapeutic proteins,
antagonists, antibodies, agonists, complementary or antisense
sequences or vectors described above may be administered in
combination with other appropriate therapeutic agents. Selection of
the appropriate agents for use in combination therapy may be made
by one of ordinary skill in the art, according to conventional
pharmaceutical principles. The combination of therapeutic agents
may act synergistically to effect the treatment or prevention of
the various disorders described above. Using this approach, one may
be able to achieve therapeutic efficacy with lower dosages of each
agent, thus reducing the potential for adverse side effects.
[0111] Antagonists or inhibitors of RLP may be produced using
methods which are generally known in the art. In particular,
purified RLP may be used to produce antibodies or to screen
libraries of pharmaceutical agents to identify those which
specifically bind RLP.
[0112] Antibodies to RLP may be generated using methods that are
well known in the art. Such antibodies may include, but are not
limited to, polyclonal, monoclonal, chimeric, single chain, Fab
fragments, and fragments produced by a Fab expression library.
Neutralizing antibodies, (i.e., those which inhibit dimer
formation) are especially preferred for therapeutic use.
[0113] For the production of antibodies, various hosts including
goats, rabbits, rats, mice, humans, and others, may be immunized by
injection with RLP or any fragment or oligopeptide thereof which
has immunogenic properties. Depending on the host species, various
adjuvants may be used to increase immunological response. Such
adjuvants include, but are not limited to, freund's, mineral gels
such as aluminum hydroxide, and surface active substances such as
lysolecithin, pluronic polyols, polyanions, peptides, oil
emulsions, keyhole limpet hemocyanin, and dinitrophenol. Among
adjuvants used in humans, BCG (bacilli Calmette-Guerin) and
Corynebacterium parvum are especially preferable.
[0114] It is preferred that the peptides, fragments, or
oligopeptides used to induce antibodies to RLP have an amino acid
sequence consisting of at least five amino acids, and more
preferably at least 10 amino acids. It is also preferable that they
are identical to a portion of the amino acid sequence of the
natural protein, and they may contain the entire amino acid
sequence of a small, naturally occurring molecule. Short stretches
of RLP amino acids may be fused with those of another protein such
as keyhole limpet hemocyanin and antibody produced against the
chimeric molecule.
[0115] Monoclonal antibodies to RLP may be prepared using any
technique which provides for the production of antibody molecules
by continuous cell lines in culture. These include, but are not
limited to, the hybridoma technique, the human B-cell hybridoma
technique, and the EBV-hybridoma technique (Kohler, G. et al.
(1975) Nature 256:495-497; Kozbor, D. et al. (1985) J. Immunol.
Methods 81:31-42; Cote, R. J. et al. (1983) Proc. Natl. Acad. Sci.
80:2026-2030; Cole, S. P. et al. (1984) Mol. Cell Biol.
62:109-120).
[0116] In addition, techniques developed for the production of
"chimeric antibodies", the splicing of mouse antibody genes to
human antibody genes to obtain a molecule with appropriate antigen
specificity and biological activity can be used (Morrison, S. L. et
al. (1984) Proc. Natl. Acad. Sci. 81:6851-6855; Neuberger, M. S. et
al. (1984) Nature 312:604-608; Takeda, S. et al. (1985) Nature
314:452-454). Alternatively, techniques described for the
production of single chain antibodies may be adapted, using methods
known in the art, to produce RLP-specific single chain antibodies.
Antibodies with related specificity, but of distinct idiotypic
composition, may be generated by chain shuffling from random
combinatorial immunoglobin libraries (Burton D. R. (1991) Proc.
Natl. Acad. Sci. 88:11120-3).
[0117] Antibodies specific for RLP may also be produced by inducing
in vivo production in the lymphocyte population or by screening
recombinant i m nunoglobulin libraries or panels of highly specific
r a y binding reagents as disclosed in the literature (Orlandi, R.
et al. (1989) Proc. Natl. Acad. Sci. 86:
[0118] 3833-3837; Winter, G. et al. (1991) Nature 349:293-299).
[0119] Antibody fragments which contain specific binding sites for
RLP may also be generated. For example, such fragments include, but
are not limited to, the F(ab')2 fragments which can be produced by
pepsin digestion of the antibody molecule and the Fab fragments
which can be generated by reducing the disulfide bridges of the
F(ab')2 fragments. Alternatively, Fab expression libraries may be
constructed to allow rapid and easy identification of monoclonal
Fab fragments with the desired specificity (Huse, W.D. et al.
(1989) Science 254:1275-1281).
[0120] Various immunoassays may be used for screening to identify
antibodies having the desired specificity. Numerous protocols for
competitive binding or immunoradiometric assays using either
polyclonal or monoclonal antibodies with established specificities
are well known in the art. Such immunoassays typically involve the
measurement of complex formation between RLP and its specific
antibody. A two-site, monoclonal-based immunoassay utilizing
monoclonal antibodies reactive to two non-interfering RLP epitopes
is preferred, but a competitive binding assay may also be employed
(Maddox, supra).
[0121] In another embodiment of the invention, the polynucleotides
encoding RLP, or any fragment thereof, or antisense molecules, may
be used for therapeutic purposes. In one aspect, antisense to the
polynucleotide encoding RLP may be used in situations in which it
would be desirable to block the transcription of the mRNA. In
particular, cells may be transformed with sequences complementary
to polynucleotides encoding RLP. Thus, antisense molecules may be
used to modulate RLP activity, or to achieve regulation of gene
function. Such technology is now well known in the art, and sense
or antisense oligomers or larger fragments, can be designed from
various locations along the coding or control regions of sequences
encoding RLP.
[0122] Expression vectors derived from retro viruses, adenovirus,
herpes or vaccinia viruses, or from various bacterial plasmids may
be used for delivery of nucleotide sequences to the targeted organ,
tissue or cell population. Methods which are well known to those
skilled in the art can be used to construct recombinant vectors
which will express antisense molecules complementary to the
polynucleotides of the gene encoding RLP. These techniques are
described both in Sambrook et al. (supra) and in Ausubel et al.
(supra).
[0123] Genes encoding RLP can be turned off by transforming a cell
or tissue with expression vectors which express high levels of a
polynucleotide or fragment thereof which encodes RLP. Such
constructs may be used to introduce untranslatable sense or
antisense sequences into a cell. Even in the absence of integration
into the DNA, such vectors may continue to transcribe RNA molecules
until they are disabled by endogenous nucleases. Transient
expression may last for a month or more with a non-replicating
vector and even longer if appropriate replication elements are part
of the vector system
[0124] As mentioned above, modifications of gene expression can be
obtained by designing antisense molecules, DNA, RNA, or PNA, to the
control regions of the gene encoding RLP, i.e., the promoters,
enhancers, and introns. Oligonucleotides derived from the
transcription initiation site, e.g., between positions -10 and +10
from the start site, are preferred. Similarly, inhibition can be
achieved using "triple helix" base-pairing methodology. Triple
helix pairing is use ful because it causes inhibition of the
ability of the double helix to open sufficiently for the binding of
polymerases, transcription factors, or regulatory molecules. Recent
therapeutic advances using triplex DNA have been described in the
literature (Gee, J.E. et al. (1994) In: Huber, B. E. and B. I.
Carr, Molecular and Immunologic Approaches, Futura Publishing Co.,
Mt. Kisco, N.Y.). The antisense molecules may also be designed to
block translation of mRNA by preventing the transcript from binding
to ribosomes.
[0125] Ribozymes, enzymatic RNA molecules, may also be used to
catalyze the specific cleavage of RNA. The mechanism of ribozyme
action involves sequence-specific hybridization of the ribozyme
molecule to complementary target RNA, followed by endonucleolytic
cleavage. Examples which may be used include engineered hammerhead
motif ribozyme molecules that can specifically and efficiently
catalyze endonucleolytic cleavage of sequences encoding RLP.
[0126] Specific ribozyme cleavage sites within any potential RNA
target are initially identified by scanning the target molecule for
ribozyme cleavage sites which include the following sequences: GUA,
GUU, and GUC. Once identified, short RNA sequences of between 15
and 20 ribonucleotides corresponding to the region of the target
gene containing the cleavage site may be evaluated for secondary
structural features which may render the oligonucleotide
inoperable. The suitability of candidate targets may also be
evaluated by testing accessibility to hybridization with
complementary oligonucleotides using ribonuclease protection
assays.
[0127] Antisense molecules and ribozymes of the invention may be
prepared by any method known in the art for the synthesis of
nucleic acid molecules. These include techniques for chemically
synthesizing o oligonucleotides such as solid phase phosphoramidite
chemical synthesis. Alternatively, RNA molecules may be generated
by in vitro and in vivo transcription of DNA sequences encoding
RLP. Such DNA sequences may be incorporated into a wide variety of
vectors with suitable RNA polymerase promoters such as T7 or SP6.
Alternatively, these cDNA constructs that synthesize antisense RNA
constitutively or inducibly can be introduced into cell lines,
cells, or tissues.
[0128] RNA molecules may be modified to increase intracellular
stability and half-life. Possible modifications include, but are
not limited to, the addition of flanking sequences at the 5' and/or
3' ends of the molecule or the use of phosphorothioate or
2'O-methyl rather than phosphodiesterase linkages within the
backbone of the molecule. This concept is inherent in the
production of PNAs and can be extended in all of these molecules by
the inclusion of nontraditional bases such as ino sine, queosine,
and wybutosine, as well as acetyl-, methyl-, thio-, and similarly
modified forms of adenine, cytidine, guanine, thymine, and uridine
which are not as easily recognized by endogenous endonucleases.
[0129] Many methods for introducing vectors into cells or tissues
are available and equally suitable for use in vivo, in vitro, and
ex vivo. For ex vivo therapy, vectors may be introduced into stem
cells taken from the patient and clonally propagated for autologous
transplant back into that same patient. Delivery by transfection
and by liposome injections may be achieved using methods which are
well known in the art.
[0130] Any of the therapeutic methods described above may be
applied to any subject in need of such therapy, including, for
example, mammals such as dogs, cats, cows, horses, rabbits,
monkeys, and most preferably, humans.
[0131] An additional embodiment of the invention relates to the
administration of a pharmaceutical composition, in conjunction with
a pharmaceutically acceptable carrier, for any of the therapeutic
effects discussed above. Such pharmaceutical compositions may
consist of RLP, antibodies to RLP, mimetics, agonists, antagonists,
or inhibitors of RLP. The compositions may be administered alone or
in combination with at least one other agent, such as stabilizing
compound, which may be administered in any sterile, biocompatible
pharmaceutical carrier, including, but not limited to, saline,
buffered saline, dextrose, and water. The compositions may be
administered to a patient alone, or in combination with other
agents, drugs or hormones.
[0132] The pharmaceutical compositions utilized in this invention
may be administered by any number of routes including, but not
limited to, oral, intravenous, intramuscular, intra-arterial,
intramedullary, intrathecal, intraventricular, transdermal,
subcutaneous, intraperitoneal, intranasal, enteral, topical,
sublingual, or rectal means.
[0133] In addition to the active ingredients, these pharmaceutical
compositions may contain suitable pharmaceutically-acceptable
carriers comprising excipients and auxiliaries which facilitate
processing of the active compounds into preparations which can be
used pharmaceutically. Further details on techniques for
formulation and administration may be found in the latest edition
of Remington's Pharmaceutical Sciences (Maack Publishing Co.,
Easton, Pa.).
[0134] Pharmaceutical compositions for oral administration can be
formulated using pharmaceutically acceptable carriers well known in
the art in dosages suitable for oral administration. Such carriers
enable the pharmaceutical compositions to be formulated as tablets,
pills, dragees, capsules, liquids, gels, syrups, slurries,
suspensions, and the like, for ingestion by the patient.
[0135] Pharmaceutical preparations for oral use can be obtained
through combination of active compounds with solid excipient,
optionally grinding a resulting mixture, and processing the mixture
of granules, after adding suitable auxiliaries, if desired, to
obtain tablets or dragee cores. Suitable excipients are
carbohydrate or protein fillers, such as sugars, including lactose,
sucrose, mannitol, or sorbitol; starch from corn, wheat, rice,
potato, or other plants; cellulose, such as methyl cellulose,
hydroxypropylmethyl-cellulose, or sodium carboxymethylcellulose;
gums including arabic and tragacanth; and proteins such as gelatin
and collagen. If desired, disintegrating or solubilizing agents may
be added, such as the cross-linked polyvinyl pyrrolidone, agar,
alginic acid, or a salt thereof, such as sodium alginate.
[0136] Dragee cores may be used in conjunction with suitable
coatings, such as concentrated sugar solutions, which may also
contain gum arabic, talc, polyvinylpyrrolidone, carbopol gel,
polyethylene glycol, and/or titanium dioxide, lacquer solutions,
and suitable organic solvents or solvent mixtures. Dyestuffs or
pigments may be added to the tablets or dragee coatings for product
identification or to characterize the quantity of active compound,
i.e., dosage.
[0137] Pharmaceutical preparations which can be used orally include
push-fit capsules made of gelatin, as well as soft, sealed capsules
made of gelatin and a coating, such as glycerol or sorbitol.
Push-fit capsules can contain active ingredients mixed with a
filler or binders, such as lactose or starches, lubricants, such as
talc or magnesium stearate, and, optionally, stabilizers. In soft
capsules, the active compounds may be dissolved or suspended in
suitable liquids, such as fatty oils, liquid, or liquid
polyethylene glycol with or without stabilizers.
[0138] Pharmaceutical formulations suitable for parenteral
administration may be formulated in aqueous solutions, preferably
in physiologically compatible buffers such as Hanks' solution,
Ringer's solution, or physiologically buffered saline. Aqueous
injection suspensions may contain substances which increase the
viscosity of the suspension, such as sodium carboxymethyl
cellulose, sorbitol, or dextran. Additionally, suspensions of the
active compounds may be prepared as appropriate oily injection
suspensions. Suitable lipophilic solvents or vehicles include fatty
oils such as sesame oil, or synthetic fatty acid esters, such as
ethyl oleate or triglycerides, or liposomes. Optionally, the
suspension may also contain suitable stabilizers or agents which
increase the solubility of the compounds to allow for the
preparation of highly concentrated solutions.
[0139] For topical or nasal administration, penetrants appropriate
to the particular barrier to be permeated are used in the
formulation. Such penetrants are generally known in the art.
[0140] The pharmaceutical compositions of the present invention may
be manufactured in a manner that is known in the art, e.g., by
means of conventional mixing, dissolving, granulating,
dragee-making, levigating, emulsifying, encapsulating, entrapping,
or lyophilizing processes. The pharmaceutical composition may be
provided as a salt and can be formed with many acids, including but
not limited to, hydrochloric, sulfuric, acetic, lactic, tartaric,
malic, succi uic, etc. Salts tend to be more soluble in aqueous or
other protonic solvents than are the corresponding free base forms.
In other cases, the preferred preparation may be a lyophilized
powder which may contain any or all of the following: 1-50 mM
histidine, 0.1%-2% sucrose, and 2-7% mannitol, at a pH range of 4.5
to 5.5, that is combined with buffer prior to use.
[0141] After pharmaceutical compositions have been prepared, they
can be placed in an appropriate container and labeled for treatment
of an indicated condition. For administration of RLP, such labeling
would include amount, frequency, and method of administration.
[0142] Pharmaceutical compositions suitable for use in the
invention include compositions wherein the active ingredients are
contained in an effective amount to achieve the intended purpose.
The determination of an effective dose is well within the
capability of those skilled in the art.
[0143] For any compound, the therapeutically effective dose can be
estimated initially either in cell culture assays, e.g., of
neoplastic cells, or in animal models, usually mice, rabbits, dogs,
or pigs. The animal model may also be used to determine the
appropriate concentration range and route of administration. Such
information can then be used to determine useful doses and routes
for administration in humans.
[0144] A therapeutically effective dose refers to that amount of
active ingredient, for example RLP or fragments thereof, antibodies
of RLP, agonists, antagonists or inhibitors of RLP, which
ameliorates the symptoms or condition. Therapeutic efficacy and
toxicity may be determined by standard pharmaceutical procedures in
cell cultures or experimental animals, e.g., ED50 (the dose
therapeutically effective in 50% of the population) and LD50 (the
dose lethal to 50% of the population). The dose ratio between
therapeutic and toxic effects is the therapeutic index, and it can
be expressed as the ratio, ED50/LD50. Pharmaceutical compositions
which exhibit large therapeutic indices are preferred. The data
obtained from cell culture assays and animal studies is used in
formulating a range of dosage for human use. The dosage contained
in such compositions is preferably within a range of circulating
concentrations that include the ED50 with little or no toxicity.
The dosage varies within this range depending upon the dosage form
employed, sensitivity of the patient, and the route of
administration.
[0145] The exact dosage will be determined by the practitioner, in
light of factors related to the subject that requires treatment.
Dosage and administration are adjusted to provide sufficient levels
of the active moiety or to maintain the desired effect. Factors
which may be taken into account include the severity of the disease
state, general health of the subject, age, weight, and gender of
the subject, diet, time and frequency of administration, drug
combination(s), reaction sensitivities, and tolerance/response to
therapy. Long-acting pharmaceutical compositions may be
administered every 3 to 4 days, every week, or once every two weeks
depending on half-life and clearance rate of the particular
formulation.
[0146] Normal dosage amounts may vary from 0.1 to 100,000
micrograms, up to a total dose of about 1 g, depending upon the
route of administration. Guidance as to particular dosages and
methods of delivery is provided in the literature and generally
available to practitioners in the art. Those skilled in the art
will employ different formulations for nucleotides than for
proteins or their inhibitors. Similarly, delivery of
polynucleotides or polypeptides will be specific to particular
cells, conditions, locations, etc.
[0147] Diagnostics
[0148] In another embodiment, antibodies which specifically bind
RLP may be used for the diagnosis of conditions or diseases
characterized by expression of RLP, or in assays to monitor
patients being treated with RLP, agonists, antagonists or
inhibitors. The antibodies useful for diagnostic purposes may be
prepared in the same manner as those described above for
therapeutics. Diagnostic assays for RLP include methods which
utilize the antibody and a label to detect RLP in human body fluids
or extracts of cells or tissues. The antibodies may be used with or
without modification, and may be labeled by joining them, either
covalently or non-covalently, with a reporter molecule. A wide
variety of reporter molecules which are known in the art may be
used, several of which are described above.
[0149] A variety of protocols including ELISA, RIA, and FACS for
measuring RLP are known in the art and provide a basis for
diagnosing altered or abnormal levels of RLP expression. Normal or
standard values for RLP expression are established by combining
body fluids or cell extracts taken from normal mam malian subjects,
preferably human, with antibody to RLP under conditions suitable
for complex formation. The amount of standard complex formation may
be quantified by various methods, but preferably by photometric
means. Quantities of RLP expressed in subject, control, and
disease, samples from biopsied tissues are compared with the
standard values. Deviation between standard and subject values
establishes the parameters for diagnosing disease.
[0150] In another embodiment of the invention, the polynucleotides
encoding RLP may be used for diagnostic purposes. The
polynucleotides which may be used include oligonucleotide
sequences, antisense RNA and DNA molecules, and PNAs. The
polynucleotides may be used to detect and quantitate gene
expression in biopsied tissues in which expression of RLP may be
correlated with disease. The diagnostic assay may be used to
distinguish between absence, presence, and excess expression of
RLP, and to monitor regulation of RLP levels during therapeutic
intervention.
[0151] In one aspect, hybridization with PCR probes which are
capable of detecting polynucleotide sequences, including geno n uc
sequences, encoding RLP or closely related molecules, may be used
to identify nucleic acid sequences which encode RLP. The
specificity of the probe, whether it is made from a highly specific
region, e.g., 10 unique nucleotides in the 5' regulatory region, or
a less specific region, e.g., especially in the 3' coding region,
and the stringency of the hybridization or amplification (maximal,
high, intennediate, or low) will determine whether the probe
identifies only naturally occurring sequences encoding RLP,
alleles, or related sequences.
[0152] Probes may also be used for the detection of related
sequences, and should preferably contain at least 50% of the
nucleotides from any of the RLP encoding sequences. The
hybridization probes of the subject invention may be DNA or RNA and
derived from the nucleotide sequence of SEQ ID NO:2 or from genomic
sequence including promoter, enhancer elements, and introns of the
naturally occurring RLP.
[0153] Means for producing specific hybridization probes for DNAs
encoding RLP include the cloning of nucleic acid sequences encoding
RLP or RLP derivatives into vectors for the production of nRNA
probes. Such vectors are known in the art, commercially available,
and may be used to synthesize RNA probes in vitro by means of the
addition of the appropriate RNA polymerases and the appropriate
labeled nucleotides. Hybridization probes may be labeled by a
variety of reporter groups, for example, radionuclides such as 32P
or 35S, or enzymatic labels, such as alkaline phosphatase coupled
to the probe via avidin jbiotin coupling systems, and the like.
[0154] Polynucleotide sequences encoding RLP may be used for the
diagnosis of disorders associated with the expression of RLP.
Examples of such disorders include: various types of cancer such as
adenocarcinoma, sarcoma, lymphoma, leukemia, melanoma, myeloma, and
cancers of the bladder, bone, brain, breast, gastrointestinal
tract, heart, kidney, liver, lung, ovary, pancreas, paraganglia,
parathyroid, prostate, skin, testis, thyroid, and uterus; disorders
associated with infla nmation such as AIDS, Addison's disease,
allergies, asthma, bronchitis, Crohn's disease, dermatomyositis,
diabetes mellitus, emphysema, Graves' disease, irritable bowel
syndrome, lupus erythematosus, myasthenia gravis, multiple
sclerosis, urethritis, rheumatoid and osteoarthritis, thyroiditis,
and ulcerative colitis. The polynucleotide sequences encoding RLP
may be used in Southern or northern analysis, dot blot, or other
membrane-based technologies; in PCR technologies; or in dip stick,
pin, ELISA or chip assays utilizing fluids or tissues from patient
biopsies to detect altered RLP expression. Such qualitative or
quantitative methods are well known in the art.
[0155] In a particular aspect, the nucleotide sequences encoding
RLP may be useful in assays that detect activation or induction of
various cancers, particularly those mentioned above. The nucleotide
sequences encoding RLP may be labeled by standard methods, and
added to a fluid or tissue sample from a patient under conditions
suitable for the formation of hybridization complexes. After a
suitable incubation period, the sample is washed and the signal is
quantitated and compared with a standard value. If the amount of
signal in the biopsied or extracted sample is significantly altered
from that of a comparable control sample, the nucleotide sequences
have hybridized with nucleotide sequences in the sample, and the
presence of altered levels of nucleotide sequences encoding RLP in
the sample indicates the presence of the associated disease. Such
assays may also be used to evaluate the efficacy of a particular
therapeutic treatment regimen in animal studies, in clinical
trials, or in monitoring the treatment of an individual
patient.
[0156] In order to provide a basis for the diagnosis of disease
associated with expression of RLP, a normal or standard profile for
expression is established. This may be accomplished by combining
body fluids or cell extracts taken from normal subjects, either
animal or human, with a sequence, or a fragment thereof, which
encodes RLP, under conditions suitable for hybridization or
amplification. Standard hybridization may be quantified by
comparing the values obtained from normal subjects with those from
an experiment where a known amount of a substantially purified
polynucleotide is used. Standard values obtained from normal
samples may be compared with values obtained from samples from
patients who are symptomatic for disease. Deviation between
standard and subject values is used to establish the presence of
disease.
[0157] Once disease is established and a treatment protocol is
initiated, hybridization assays may be repeated on a regular basis
to evaluate whether the level of expression in the patient begins
to approximate that which is observed in the normal patient. The
results obtained from successive assays may be used to show the
efficacy of treatment over a period ranging from several days to
months.
[0158] With respect to cancer, the presence of a relatively high
amount of transcript in biopsied tissue from an individual may
indicate a predisposition for the development of the disease, or
may provide a means for detecting the disease prior to the
appearance of actual clinical symptoms. A more definitive diagnosis
of this type may allow health professionals to employ preventative
measures or aggressive treatment earlier thereby preventing the
development or further progression of the cancer.
[0159] Additional diagnostic uses for oligonucleotides designed
from the sequences encoding RLP may involve the use of PCR. Such
oligomers may be chemically synthesized, generated enzymatically,
or produced from a recombinant source. Oligomers will preferably
consist of two nucleotide sequences, one with sense orientation
(5'->3') and another with antisense (3<-5'), employed under
optimized conditions for identification of a specific gene or
condition. The same two oligomers, nested sets of oligomers, or
even a degenerate pool of oligomers may be employed under less
stringent conditions for detection and/or quantitation of closely
related DNA or RNA sequences.
[0160] Methods which may also be used to quantitate the expression
of RLP include radiolabeling or biotinylating nucleotides,
coamplification of a control nucleic acid, and standard curves onto
which the experimental results are interpolated (Melby, P. C. et
al. (1993) J. Immunol. Methods, 159:235-244; Duplaa, C. et al.
(1993) Anal. Biochem. 229-236). The speed of quantitation of
multiple samples may be accelerated by running the assay in an
ELISA format where the oligomer of interest is presented in various
dilutions and a spectrophotometric or colorimetric response gives
rapid quantitation.
[0161] In another embodiment of the invention, the nucleic acid
sequences which encode RLP may also be used to generate
hybridization probes which are useful for mapping the naturally
occurring genonic sequence. The sequences may be mapped to a
particular chromosome or to a specific region of the chromosome
using well known techniques. Such techniques include FISH, FACS, or
artificial chromosome constructions, such as yeast artificial
chromosomes, bacterial artificial chromosomes, bacterial P1
constructions or single chromosome cDNA libraries as reviewed in
Price, C. M. (1993) Blood Rev. 7:127-134, and Trask, B. J. (1991)
Trends Genet. 7:149-154.
[0162] FISH (as described in Verma et al. (1988) Human Chromosomes:
A Manual of Basic Techniques, Pergamon Press, New York, N.Y.) may
be correlated with other physical chromosome mapping techniques and
genetic map data. Examples of genetic map data can be found in the
1994 Genome Issue of Science (265:1981fill). Correlation between
the location of the gene encoding RLP on a physical chromosomal map
and a specific disease, or predisposition to a specific disease,
may help delimit the region of DNA associated with that genetic
disease. The nucleotide sequences of the subject invention may be
used to detect differences in gene sequences between normal,
carrier, or affected individuals.
[0163] In situ hybridization of chromosomal preparations and
physical mapping techniques such as linkage analysis using
established chromosomal markers may be used for extending genetic
maps. Often the placement of a gene on the chromosome of another
mammalian species, such as mouse, may reveal associated markers
even if the nuriber or arm of a particular human chromosome is not
known. New sequences can be assigned to chromosomal arms, or parts
thereof, by physical mapping. This provides valuable information to
investigators searching for disease genes using positional cloning
or other gene discovery techniques. Once the disease or syndrome
has been crudely localized by genetic linkage to a particular
genomic region, for example, AT to 11q22-23 (Gatti, R. A. et al.
(1988) Nature 336:577-580), any sequences mapping to that area may
represent associated or regulatory genes for further investigation.
The nucleotide sequence of the subject invention may also be used
to detect differences in the chromosomal location due to
translocation, inversion, etc. among normal, carrier, or affected
individuals.
[0164] In another embodiment of the invention, RLP, its catalytic
or immunogenic fragments or oligopeptides thereof, can be used for
screening libraries of compounds in any of a variety of drug
screening techniques. The fragment employed in such screening may
be free in solution, affixed to a solid support, borne on a cell
surface, or located intracellularly. The formation of binding
complexes, between RLP and the agent being tested, may be
measured.
[0165] Another technique for drug screening which may be used
provides for high throughput screening of compounds having suitable
binding affinity to the protein of interest as described in
published PCT application WO84/03564. In this method, as applied to
RLP large numbers of different small test compounds are synthesized
on a solid substrate, such as plastic pins or some other surface.
The test compounds are reacted with RLP, or fragments thereof, and
washed. Bound RLP is then detected by methods well known in the
art. Purified RLP can also be coated directly onto plates for use
in the aforementioned drug screening techniques. Alternatively,
non-neutralizing antibodies can be used to capture the peptide and
immobilize it on a solid support.
[0166] In another embodiment, one may use competitive drug
screening assays in which neutralizing antibodies capable of
binding RLP specifically compete with a test compound for binding
RLP. In this manner, the antibodies can be used to detect the
presence of any peptide which shares one or more antigenic
determinants with RLP.
[0167] In additional enibodiments, the nucleotide sequences which
encode RLP may be used in any molecular biology techniques that
have yet to be developed, provided the new techniques rely on
properties of nucleotide sequences that are currently known,
including, but not limited to, such properties as the triplet
genetic code and specific base pair interactions.
[0168] The examples below are provided to illustrate the subject
invention and are not included for the purpose of limiting the
invention.
EXAMPLES
[0169] I UTRSNOT02 cDNA Library Construction
[0170] The normal tissue used for uterus cDNA library construction
was obtained from a 34 year-old female. The frozen tissue was
homogenized and lysed using a Brinkmann Homogenizer Polytron
PT-3000 (Brinkma nm Instruments, Westbury, N.J.). The reagents and
extraction procedures were used as supplied in the Stratagene RNA
Isolation Kit (Catalog #200345; Stratagene). The lysate was
centrifuged over a 5.7 M CsCl cushion using a Beckman SW28 rotor in
a Beckman L8-70M Ultracentrifuge (Beckman Instruments) for 18 hours
at 25,000 rpm at ambient temperature. The RNA was extracted three
times with acid phenol pH 4.0, precipitated using 0.3 M sodium
acetate and 2.5 volumes of ethanol, resuspended in water and DNase
treated for 15 min at 37.degree. C. The RNA was isolated using the
QIAGEN OLIGOTEX kit (QIAGEN Inc, Chatsworth, Calif.) and used to
construct the cDNA library.
[0171] The RNA was handled according to the recommended protocols
in the SuperScript Plasmid System for cDNA Synthesis and Plasmid
Clo uing (Catalog #18248-013, Gibco/BRL, Gaithersburg, MD), cDNAs
were fractionated on a Sepharose CL4B column (Catalog #275105,
Pharmacia) and ligated into the PSPORT 1 plasmid. The plasmid was
subsequently transformed into DH5.alpha. competent cells (Catalog
#18258-012, Gibco/BRL).
[0172] II Isolation and Sequencing of cDNA Clones
[0173] Plasmid DNA was released from the cells and purified using
the Miniprep Kit (Catalog #77468; Advanced Genetic Technologies
Corporation, Gaithersburg, MD). This kit consists of a 96-well
block with reagents for 960 purifications. The recommended protocol
was employed except for the following changes: 1) the 96 wells were
each filled with only 1 n m of sterile Terrific Broth (Catalog
#22711, Gibco/BRL) with carbenicillin at 25 mg/L and glycerol at
0.4%; 2) the bacteria were cultured for 24 hours after the wells
were inoculated and then lysed with 60 .mu.l of lysis buffer; 3) a
centrifugation step employing the Beckman GS-6R rotor at 2900 rpm
for 5 minutes was performed before the contents of the block were
added to the primary filter plate; and 4) the optional step of
adding isopropanol to TRIS buffer was not routinely performed.
After the last step in the protocol, samples were transferred to a
Beckman 96-well block for storage.
[0174] The cDNAs were sequenced by the method of Sanger F and AR
Coulson (1975; J Mol Biol 94:441fill), using a Hamiton Micro Lab
2200 (Hamilton, Reno, Nev.) in combination with four Peltier
Thermal Cyclers (PTC200 from MJ Research, Watertown, Mass.) and
Applied Biosystems 377 or 373 DNA Sequencing Systems, and the
reading frame was determined.
[0175] III Homology Searching of cDNA Clones and Their Deduced
Proteins
[0176] After the reading frame was determined, the nucleotide
sequences of the Sequence Listing or amino acid sequences deduced
from them were used as query sequences against databases such as
GenBank, SwissProt, BLOCKS, and Pima II. These databases which
contain previously identified and annotated sequences, were
searched for regions of homology (similarity) using BLAST, which
stands for Basic Local Alignment Search Tool (Altschul (1993)
supra, Altschul (1990) supra).
[0177] BLAST produced alignments of both nucleotide and amino acid
sequences to determine sequence si milarity. Because of the local
nature of the alignments, BLAST was especially useful in
determining exact matches or in identifying homologs which may be
of prokaryotic (bacterial) or eukaryotic (animal, fungal, or plant)
origin. Other algorithms such as the one described in Smith et al.
(1992, Protein Engineering 5:35-51), incorporated herein by
reference, could have been used when dealing with pri try sequence
patterns and secondary structure gap penalties. The sequences
disclosed in this application have lengths of at least 49
nucleotides, and no more than 12% uncalled bases (where N is
recorded rather than A, C, G, or T).
[0178] The BLAST approach, as detailed in Karlin et al. (supra) and
incorporated herein by reference, searched for matches between a
query sequence and a database sequence. BLAST evaluated the
statistical significance of any matches found, and reported only
those matches that satisfy the user-selected threshold of
significance. In this application, threshold was set at 10-25 for
nucleotides and 10.sup.-14 for peptides.
[0179] IV Northern Analysis
[0180] Northern analysis is a laboratory technique used to detect
the presence of a transcript of a gene and involves the
hybridization of a labeled nucleotide sequence to a membrane on
which RNAs from a particular cell type or tissue have been bound
(Sambrook et al., supra).
[0181] Analogous computer techniques using BLAST (Altschul, S. F.
1993 and 1990, supra) are used to search for identical or related
molecules in nucleotide databases such as GenBank or the
LIFESEQ.TM. database (Incyte Pharmaceuticals). This analysis is
much faster than multiple, membrane-based hybridizations. In
addition, the sensitivity of the computer search can be modified to
determine whether any particular match is categorized as exact or
homologous.
[0182] The basis of the search is the product score which is
defined as: 1 % sequence identity .times. % maximum BLAST score
100
[0183] The product score takes into account both the degree of si
milarity between two sequences and the length of the sequence
match. For example, with a product score of 40, the match will be
exact within a 1-2% error; and at 70, the match will be exact.
Homologous molecules are usually identified by selecting those
which show product scores between 15 and 40, although lower scores
may identify related molecules.
[0184] The results of northern analysis are reported as a list of
libraries in which the transcript encoding RLP occurs. Abundance
and percent abundance are also reported. Abundance directly
reflects the number of times a particular transcript is represented
in a cDNA library, and percent abundance is abundance divided by
the total number of sequences examined in the cDNA library.
[0185] V Extension of RLP-Encoding Polynucleotides
[0186] Nucleic acid sequence of Incyte clone 683101 or SEQ ID NO:2
is used to design oligonucleotide primers for extending a partial
nucleotide sequence to full length or for obtaining 5' or 3',
intron or other control sequences from genomic libraries. One
primer is synthesized to initiate extension in the antisense
direction (XLR) and the other is synthesized to extend sequence in
the sense direction (XLF). Primers are used to facilitate the
extension of the known sequence "outward," generating amplicons
containing new, unknown nucleotide sequence for the region of
interest. The initial primers are designed from the cDNA using
OLIGO 4.06 (National Biosciences), or another appropriate program,
to be 22-30 nucleotides in length, to have a GC content of 50% or
more, and to anneal to the target sequence at temperatures about
68.degree.-72.degree. C. Any stretch of nucleotides which would
result in hairpin structures and primer-primer di rerizations is
avoided.
[0187] The original, selected cDNA libraries, or a human genomic
library are used to extend the sequence; the latter is most useful
to obtain 5' upstream regions. If more extension is necessary or
desired, additional sets of primers are designed to further extend
the known region.
[0188] By following the instructions for the XL-PCR kit (Perkin
Ehner) and thoroughly mixing the enzyme and reaction mix, high
fidelity amplification is obtained. Beginning with 40 pmol of each
primer and the recommended concentrations of all other components
of the kit, PCR is performed using the Peltier Thermal Cycler
(PTC200; M. J. Research, Watertown, Mass.) and the following
parameters:
1 Step 1 94.degree. C. for 1 min (initial denaturation) Step 2
65.degree. C. for 1 min Step 3 68.degree. C. for 6 min Step 4
94.degree. C. for 15 sec Step 5 65.degree. C. for 1 min Step 6
68.degree. C. for 7 min Step 7 Repeat step 4-6 for 15 additional
cycles Step 8 94.degree. C. for 15 sec Step 9 65.degree. C. for 1
min Step 10 68.degree. C. for 7:15 min Step 11 Repeat step 8-10 for
12 cycles Step 12 72.degree. C. for 8 min Step 13 4.degree. C. (and
holding)
[0189] A 5-10 .mu.l aliquot of the reaction mixture is analyzed by
electrophoresis on a low concentration (about 0.6-0.8%) agarose
mini-gel to determine whichreactions were successful in extending
the sequence. Bands thought to contain the largest products are
selected and removed from the gel. Further purification involves
using a commercial gel extraction method such as QIAQUICK (QIAGEN
Inc., Chatsworth, Calif.). After recovery of the DNA, Klenow enzyme
is used to trim single-stranded, nucleotide overhangs creating
blunt ends which facilitate religation and clo rn ig.
[0190] After ethanol precipitation, the products are redissolved in
13 .mu.l of ligation buffer, 1 .mu.l T4-DNA ligase (15 units) and 1
.mu.l T4 polynucleotide kinase are added, and the mixture is
incubated at room temperature for 2-3 hours or overnight at
16.degree. C. Competent E. coli cells (in 40 .mu.l of appropriate
media) are transformed with 3 .mu.l of ligation mixture and
cultured in 80 al of SOC medium (Sambrook et al., supra). After
incubation for one hour at 37.degree. C., the whole transformation
mixture is plated on Luria Bertani (LB)-agar (Sambrook et al.,
supra) containing 2.times. Carb. The following day, several
colonies are randomly picked from each plate and cultured in 150
.mu.l of liquid LB/2.times. Carb medium placed in an individual
well of an appropriate, commercially-available, sterile 96-well
microtiter plate. The following day, 5 .mu.l of each overnight
culture is transferred into a non-sterile 96-well plate and after
dilution 1:10 with water, 5 .mu.l of each sample is transferred
into a PCR array.
[0191] For PCR amplification, 18 Al of concentrated PCR reaction
mix (3.3.times.) containing 4 units of rTth DNA polymerase, a
vector primer, and one or both of the gene specific primers used
for the extension reaction are added to each well. Amplification is
performed using the following conditions:
2 Step 1 94.degree. C. for 60 sec Step 2 94.degree. C. for 20 sec
Step 3 55.degree. C. for 30 sec Step 4 72.degree. C. for 90 sec
Step 5 Repeat steps 2-4 for an additional 29 cycles Step 6
72.degree. C. for 180 sec Step 7 4.degree. C. (and holding)
[0192] Aliquots of the PCR reactions are run on agarose gels
together with molecular weight markers. The sizes of the PCR
products are compared to the original partial cDNAs, and
appropriate clones are selected, ligated into plasmid, and
sequenced.
[0193] VI Labeling and Use of Hybridization Probes
[0194] Hybridization probes derived from SEQ ID NO:2 are employed
to screen cDNAs, geno rnic DNAs, or m RNAs. Although the labeling
of oligonucleotides, consisting of about 20 base-pairs, is
specifically described, essentially the same procedure is used with
larger cDNA fragments. Oligonucleotides are designed using
state-of-the-art software such as OLIGO 4.06 (National
Biosciences), labeled by combining 50 pmol of each oligomer and 250
.mu.Ci of [.gamma.-.sup.32P] adenosine triphosphate (Amersham) and
T4 polynucleotide kinase (DuPont NEN .RTM., Boston, MA). The
labeled oligonucleotides are substantially purified with Sephadex
G-25 superfine resin column (Pharmacia & Upjohn). A portion
containing 10.sup.7 counts per minute of each of the sense and
antisense oligonucleotides is used in a typical membrane based
hybridization analysis of human genor nic DNA digested with one of
the following endonucleases (Ase I, Bgl II, Eco RI, Pst I, Xba 1,
or Pvu II; DuPont NEN.RTM.).
[0195] The DNA from each digest is fractionated on a 0.7 percent
agarose gel and transferred to nylon membranes (Nytran Plus,
Schleicher & Schuell, Durham, N.H.). Hybridization is carried
out for 16 hours at 40.degree. C. To remove nonspecific signals,
blots are sequentially washed at room temperature under
increasingly stringent conditions up to 0.1 .times. saline sodium
citrate and 0.5% sodium dodecyl sulfate. After XOMAT AR.TM. film
(Kodak, Rochester, N.Y.) is exposed to the blots in a Phosphoh
nager cassette (Molecular Dyna mics, Sunnyvale, Calif.) for several
hours, hybridization patterns are compared visually.
[0196] VII Antisense or Complementary Sequences
[0197] Antisense molecules or nucleic acid sequences complementary
to the RLP-encoding sequence, or any part thereof, are used to
inhibit in vivo or in vitro expression of naturally occurring RLP.
Although use of antisense oligonucleotides, comprising about 20
base-pairs, is specifically described, essentially the same
procedure is used with larger cDNA fragments. An oligonucleotide
based on the coding sequences of RLP, as shown in FIGS. 1A, 1B and
1C, is used to inhibit expression of naturally occurring RLP. The
complementary oligonucleotide is designed from the most unique 5'
sequence as shown in FIGS. 1A, 1B and 1C and used either to inhibit
transcription by preventing promoter binding to the upstream
nontranslated sequence or translation of an RLP-encoding transcript
by preventing the ribosome from binding. Using an appropriate
portion of the signal and 5' sequence of SEQ ID NO:2, an effective
antisense oligonucleotide includes any 15-20 nucleotides spanning
the region which translates into the signal or 5' coding sequence
of the polypeptide as shown in FIGS. 1A, 1B and 1C.
[0198] VIII Expression of RLP
[0199] Expression of RLP is accomplished by subcloning the cDNAs
into appropriate vectors and transforming the vectors into host
cells. In this case, the PSPORT 1 cloning vector, previously used
for the generation of the cDNA library, is used to express RLP in
E. coli. Upstream of the cloning site, this vector contains a
promoter for B-galactosidase, followed by sequence containing the
amino-terminal Met, and the subsequent seven residues of
.beta.-galactosidase. Immediately following these eight residues is
a bacteriophage promoter useful for transcription and a linker
containing a number of unique restriction sites.
[0200] Induction of an isolated, transformed bacterial strain with
IPTG using standard methods produces a fusion protein which
consists of the first eight residues of .beta.-galactosidase, about
5 to 15 residues of linker, and the full length protein. The signal
residues direct the secretion of RLP into the bacterial growth
media which can be used directly in the following assay for
activity.
[0201] IX Demonstration of RLP Activity
[0202] RLP can be expressed in a mammalian cell line such as 293T
by transfecting with an eukaryotic expression vector encoding RLP.
Eukaryotic expression vectors are commercially available, and the
techniques to introduce them into cells are well known to those
skilled in the art. A small amount of a second plasmid, wh ich
expresses any one of a number of reporter genes such as
.gamma.-galactosidase, is co-transformed into the cells in order to
allow rapid identification of those cells which have taken up and
expressed the foreign DNA. The cells are cultured in a defined
synthetic medium with concentrations of GTP for at least 48 hours
after transformation to allow expression and accumulation of RLP
and .gamma.-galactosidase.
[0203] Transformed cells expressing .gamma.-galactosidase are
stained blue when a suitable calorimetric substrate is added to the
culture media under conditions that are well known in the art.
Increasing concentrations of GTP induces increasing numbers of
reporter gene positive cells (Ren, M. et al. (1996) Proc. Natl.
Acad. Sci. 93: 5151-5155). GTP-treated cells which were not
transformed with the RLP expression vector are used as controls as
are RLP transfected cells cultured without supplemental GTP.
[0204] X Production of RLP Specific Antibodies
[0205] RLP that is substantially purified using PAGE
electrophoresis (Sambrook, supra), or other purification
techniques, is used to immunize rabbits and to produce antibodies
using standard protocols.
[0206] The amino acid sequence deduced from SEQ ID NO:2 is analyzed
using DNASTAR software (DNASTAR Inc) to determine regions of high
immunogenicity and a corresponding oligopolypeptide is synthesized
and used to raise antibodies by means known to those of skill in
the art. Selection of appropriate epitopes, such as those near the
C-terminus or in hydrophilic regions, is described by Ausubel et
al. (supra), and others.
[0207] Typically, the oligopeptides are 15 residues in length,
synthesized using an Applied Biosystems Peptide Synthesizer Model
431A using fmoc-chemistry, and coupled to keyhole limpet hemocyanin
(KLH, Sigma, St. Louis, Mo.) by reaction with
N-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS; Ausubel et al.,
supra). Rabbits are immunized with the o ligopeptide-KlI complex in
complete Freund's adjuvant. The resulting antisera are tested for
antipeptide activity, for example, by binding the peptide to
plastic, blocking with 1% BSA, reacting with rabbit antisera,
washing, and reacting with radioiodinated, goat anti-rabbit
IgG.
[0208] XI Puirification of Naturally Occurring RLP Using Specific
Antibodies
[0209] Naturally occurring or recombinant RLP is substantially
purified by immunoaffinity chromatography using antibodies specific
for RLP. An immunoaffinity column is constructed by covalently
coupling RLP antibody to an activated chromatographic resin, such
as CnBr-activated Sepharose (Pharmacia & Upjohn). After the
coupling, the resin is blocked and washed according to the
manufacturer's instructions.
[0210] Media containing RLP is passed over the i munoaffinity
column, and the column is washed under conditions that allow the
preferential absorbance of RLP (e.g., high ionic strength buffers
in the presence of detergent). The colun n is eluted under
conditions that disrupt antibodylRLP binding (eg, a buffer of pH
2-3 or a high concentration of a chaotrope, such as urea or
thiocyanate ion), and RLP is collected.
[0211] XII Identification of Molecules Which Interact with RLP
[0212] RLP or biologically active fragments thereof are labeled
with .sup.125I Bolton-Hunter reagent (Bolton et al. (1973) Biocheim
J. 133: 529). Candidate molecules previously arrayed in the wells
of a multi-well plate are incubated with the labeled RLP, washed
and any wells with labeled RLP complex are assayed. Data obtained
using different concentrations of RLP are used to calculate values
for the number, affinity, and association of RLP with the candidate
molecules.
[0213] All publications and patents mentioned in the above
specification are herein incorporated by reference. Various
modifications and variations of the described method and system of
the invention will be apparent to those skilled in the art without
departing from the scope and spirit of the invention. Although the
invention has been described in connection with specific preferred
embodiments, it should be understood that the invention as claimed
should not be unduly limited to such specific embodiments. Indeed,
various modifications of the described modes for carrying out the
invention which are obvious to those skilled in molecular biology
or related fields are intended to be within the scope of the
following claims.
Sequence CWU 1
1
* * * * *