U.S. patent application number 10/222668 was filed with the patent office on 2003-05-08 for mammalian relaxin receptors.
Invention is credited to Hsu, Sheau Yu, Hsueh, Aaron J.W..
Application Number | 20030088884 10/222668 |
Document ID | / |
Family ID | 23215001 |
Filed Date | 2003-05-08 |
United States Patent
Application |
20030088884 |
Kind Code |
A1 |
Hsu, Sheau Yu ; et
al. |
May 8, 2003 |
Mammalian relaxin receptors
Abstract
High affinity relaxin receptors, polypeptide compositions
related thereto, as well as nucleotide compositions encoding the
same, are provided. These proteins, herein termed LGR7 and LGR8,
are orphan leucine-repeat-containi- ng, G protein-coupled
receptors. These receptors have a wide and a unique tissue
expression pattern. The receptors, particularly soluble fragments
thereof, are useful as therapeutic agents capable of inhibiting the
action of relaxin and InsL3. The receptors and fragments thereof
also find use in the screening and design of relaxin agonists and
antagonists. Conditions treatable with relaxin agonists or
antagonists include prevention or induction of labor, treatment of
endometriosis, treatment of skin conditions such as scleroderma
that require collagen or extracellular matrix remodelling.
Additionally, relaxin has been implicated in the dilation of blood
vessels' smooth muscle cells directly and through release of nitric
oxide and atrial natriuretic peptide. Relaxin has also been used in
the treatment of severe chronic pain, particularly pain arising
from stretching, swelling, or dislocation of tissues.
Inventors: |
Hsu, Sheau Yu; (Mountain
View, CA) ; Hsueh, Aaron J.W.; (Stanford,
CA) |
Correspondence
Address: |
BOZICEVIC, FIELD & FRANCIS LLP
200 MIDDLEFIELD RD
SUITE 200
MENLO PARK
CA
94025
US
|
Family ID: |
23215001 |
Appl. No.: |
10/222668 |
Filed: |
August 15, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60313259 |
Aug 17, 2001 |
|
|
|
Current U.S.
Class: |
800/9 ; 435/7.1;
514/12.7; 514/20.1; 514/20.6; 530/388.25; 536/23.5 |
Current CPC
Class: |
A61K 38/00 20130101;
A61P 15/04 20180101; A61P 15/06 20180101; C07K 14/723 20130101 |
Class at
Publication: |
800/9 ; 514/12;
536/23.5; 530/388.25; 435/7.1 |
International
Class: |
A01K 067/00; G01N
033/53; A61K 038/17; C07H 021/04 |
Claims
What is claimed is:
1. A composition comprising an LGR8 polypeptide, comprising at
least 18 contiguous amino acids of the sequence set forth in SEQ ID
NO:2.
2. A composition according to claim 1, wherein said LGR8
polypeptide is a soluble fragment of LGR8.
3. A composition according to claim 1, wherein said LGR8
polypeptide comprises a mutation that confers a gain of
function.
4. A composition comprising an LGR7 polypeptide, wherein said
polypeptide is a soluble fragment of LGR7.
5. The composition according to claim 2, wherein said composition
further comprises a pharmaceutically acceptable carrier.
6. The composition according to claim 4, wherein said composition
further comprises a pharmaceutically acceptable carrier.
7. A method of inhibiting premature labor, the method comprising
administering a patient suffering from premature labor the
composition according to claim 2.
8. A method of inhibiting premature labor, the method comprising
administering a patient suffering from premature labor the
composition according to claim 5.
9. An isolated nucleic acid molecule comprising a cDNA sequence
encoding a mammalian LGR8 polypeptide that will hybridize under
stringent conditions of 50.degree. C. or higher in the presence of
0.1.times.SSC to the sequence set forth in SEQ ID NO:1, or encodes
the peptide of SEQ ID NO:2.
10. An antibody that specifically recognizes a relaxin
receptor.
11. A non-human transgenic animal model for relaxin receptor gene
function wherein said transgenic animal comprises an introduced
alteration in a LGR7 or LGR8 gene.
12. A method of screening for biologically active agents that
modulate relaxin function, the method comprising: combining a
candidate biologically active agent with any one of: (a) an LGR7 or
LGR8 polypeptide; (b) a cell comprising a nucleic acid encoding an
LGR7 or LGR8 polypeptide; or (c) a non-human transgenic animal
model for relaxin receptor gene function comprising one of: (i) a
knockout of an LGR7 or LGR8 gene; (ii) an exogenous and stably
transmitted LGR7 or LGR8 gene; and determining the effect of said
agent on relaxin function.
13. A method of screening for biologically active agents that
modulate InsL3 function, the method comprising: combining a
candidate biologically active agent with any one of: (a) an LGR8
polypeptide; (b) a cell comprising a nucleic acid encoding an LGR8
polypeptide; or (c) a non-human transgenic animal model for relaxin
receptor gene function comprising one of: (i) a knockout of an LGR8
gene; (ii) an exogenous and stably transmitted LGR8 gene; and
determining the effect of said agent on LGR8 function.
14. A method of designing biologically active agents that modulate
LGR7 or LGR8 function, the method comprising: determining the
binding sites between LGR8 or LGR7 and a cognate ligand; designing
a pharmacomimetic molecule that mimics the binding site of either
said LGR8 or LGR7; or the binding site of said cognate ligand.
15. The method according to claim 13, wherein said cognate ligand
is relaxin or InsL3.
16. A method for the treatment of cryptorchidism, the method
comprising: administering to an individual suffering from said
cryptorchidism an agonist of LGR8 in a pharmaceutically effective
dose.
17. A method for the treatment of scleroderma, the method
comprising: administering to an individual suffering from said
scleroderma an agonist of LGR7 or LGR8 in a pharmaceutically
effective dose.
18. A method for the induction of labor, the method comprising:
administering to an individual for which induction of labor is
desired, an agonist of LGR7 or LGR8 in a pharmaceutically effective
dose.
19. A method for the diagnosis of a genetic condition associated
LGR8 or LGR7, the method comprising: analyzing a sample of a
patient suspected of said genetic condition for expression or
sequence of LGR7 or LGR8, wherein an alteration in expression or
sequence as compared to a normal sample is indicative of said
genetic condition.
20. The method according to claim 19, wherein said condition is
cryptorchidism.
Description
BACKGROUND OF THE INVENTION
[0001] Relaxin is a pregnancy hormone discovered in 1926 (Hisaw
(1926) Proc. Soc. Exp. Biol. Med. 23: 661-663), based on its
ability to relax the public ligament in guinea pig. Mature human
relaxin is a hormonal peptide of approximately 6000 daltons known
to be responsible for remodelling the reproductive tract before
parturition, thus facilitating the birth process. A concise review
of relaxin was provided by Sherwood, D. in The Physiology of
Reproduction, Chapter 16, "Relaxin", Knobil, E. and Neill, J., et
al. (eds.), (Raven Press Ltd., New York), pp. 585-673 (1988).
Relaxin has local autocrine and/or paracrine roles that contribute
to connective tissue remodeling at the maternal-fetal interface
during late pregnancy and at parturition, including an increase in
the expression of the genes, proteins, and enzyme activities of the
matrix metalloproteinases interstitial collagenase (MMP-1),
stromelysin (MMP-3), and gelatinase B (MMP-9).
[0002] Two human gene forms of relaxin have been identified, (H1)
and (H2) (Hudson et al. (1983) Nature 301:628-631; Hudson et al.
(1984) EMBO Journal 3:2333-2339; U.S. Pat. Nos. 4,758,516 and
4,871,670). Only the H2 form is expressed in corpus luteum. The
primary translation product of H2 relaxin is a preprorelaxin
consisting of a 24 amino acid signal sequence followed by a B chain
of about 29 amino acids, a connecting peptide of 104-107 amino
acids, and an A chain of about 24 amino acids.
[0003] Although relaxin itself has been well-characterized for a
number of years, it's receptor has remained elusive. To date,
binding studies have had to rely on crude cellular extracts, which
indicated that a specific binding molecule was present, but gave no
clue as to its molecular identity. Relaxin binding sites have been
reported in the reproductive tract (Kohsaka et al. (1998) Biol
Reprod 59(4):991-9), as well as other tissues, including cardiac
and other smooth muscle, and specific nuclei in the brain (Tan et
al. (1999) Br J Pharmacol 127(1):91-8).
[0004] During fetal development, the sexual dimorphic position of
the gonads in mammals is dependent on the differential development
of two ligaments. In males, growth of the gubernaculum and
regression of the cranial suspensory ligament results in
transabdominal descent of the testes. Impaired testicular descent
(cryptorchidism) is a prevalent congenital abnormality in humans,
found in 2% of male births. INSL3, also known as Leydig
insulin-like peptide or relaxin-like factor (RLF), is one of the
seven relaxin-like genes in humans known to be expressed in Leydig
cells of fetal and adult testes as well as in theca and luteal
cells of the postnatal ovary (Ivell (1997) Rev. Reprod. 2, 133-8).
Male mice mutant for INSL3 exhibit bilateral abdominal
cryptorchidism whereas female mice overexpressing INSL3 showed
ovary descent and displayed bilateral inguinal hernia. Although
INSL3 binds to gubernacular homogenates (Boockfor et al. (2001)
Reproduction 122, 899-906) and induces growth of rat gubernaculum
in whole organ cultures (Smith et al. (2001) J. Pept. Sci. 7,
495-501), the exact nature of the INSL3 receptor is unknown. A
recent study indicated that transgene integration in crsp mice
resulted in a 550-kb deletion located upstream of the Brca2 gene,
leading to defective testis descent (Overbeek et al. (2001) Genesis
30, 26-35).
[0005] The identification and molecular characterization of relaxin
receptors is of great scientific and clinical interest.
Understanding of relaxin signaling mechanisms mediated by its
receptor can provide new approaches for the regulation of relaxin
target tissues during pregnant and non-pregnant states.
SUMMARY OF THE INVENTION
[0006] High affinity relaxin receptors, polypeptide compositions
related thereto, as well as nucleotide compositions encoding the
same, are provided. These proteins, herein termed LGR7 and LGR8,
are orphan leucine-repeat-containing, G protein-coupled receptors,
and are paralogs of gonadotropin and thyrotropin receptors. These
receptors have a wide and unique tissue expression pattern. LGR8 is
a receptor for InsL3, which has been shown to be important for
testis descent. Treatment of antepartum animals with the soluble
ligand-binding region of LGR7 has led to parturition delay. Thus,
relaxin and InsL3 signal through G protein-coupled receptors
distinct from the related insulin family of ligands in regulating
pregnancy-related processes.
[0007] The receptors, particularly soluble fragments thereof, are
useful as therapeutic agents capable of inhibiting the action of
relaxin. The receptors and fragments thereof also find use in the
screening and design of relaxin agonists and antagonists.
Conditions treatable with relaxin agonists or antagonists include
prevention or induction of labor, treatment of endometriosis,
treatment of skin conditions such as scleroderma that require
collagen or extracellular matrix remodelling. Additionally, relaxin
has been implicated in the dilation of blood vessels' smooth muscle
cells directly and through release of nitric oxide and atrial
natriuretic peptide. Relaxin has also been used in the treatment of
severe chronic pain, particularly pain arising from stretching,
swelling, or dislocation of tissues.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1. Cloning of LGR8 and elucidation of its signaling
mechanism. A) Sequence alignment of human LGR8 (Accession No.
AF403384) with homologous receptors belong to the same subgroup of
LGRs (human LGR7, a snail LGR and a Drosophila LGR). The sequence
identity of human LGR8 was first deduced from high throughput
genomic sequences using gene prediction programs GRAIL-1.3,
FGENES-M, and NNPP located at BCM Launcher server, followed by
subcloning using 5' and 3' RACE using gene-specific primers and
Marathon-ready cDNA template (Clontech Inc., Palo Alto, Calif.)
from human ovary, testis, pituitary, brain, and uterus. Amino acid
numbers are on the right and the stop codon is marked with an
asterisk. Putative N-glycosylation sites are circled. Identical
residues are highlighted by a dark background. The N-terminal
signal peptide for secretion in each polypeptide is underlined. The
consensus LDL receptor cysteine-rich motifs are indicated by bold
italics. Different structural motifs including the transmembrane
(TM) region, intracellular loop (IL), and extracellular loop (EL),
are indicated by arrowheads. Shaded residues are identical in the
human LGR7 and snail LGR sequences. Residue numbers are shown on
the right and gaps are included for optimal protein alignment. The
BLOCK Maker program was used to align and generate the highly
conserved ungapped blocks of the aligned LGR polypeptides from
different species. B) Phylogenetic relatedness of diverse LGRs from
mammals and invertebrates. Full-length amino acid sequences of 11
LGRs from mammals (LH, FSH, and TSH receptors plus LGR4 to LGR8),
sea anemone, nematode, pond snail, and Drosophila were analyzed by
the neighboring-joining method from the Block alignments using a
routine in CLUSTALW. h: human; s: pond snail; Dm: Drosophila
melanogaster analyzed using the Blocks program. These LGRs could be
divided into three major branches; the first subgroup include the
three classical human glycoprotein hormone receptors as well as
LGRs from sea anemone, nematode, and Drosophila, the second group
includes human LGR4-6 and Drosophila LGR2, whereas the third
subgroup includes human LGR7-8 and Drosophila LGR3. C) A
gain-of-function LGR8 mutant mediated constitutive cAMP production
in transfected cells. Based on the gain-of-function point mutation
(LHR D578Y) found in the LH receptor gene of patients with familial
male-limited precocious puberty, LGR8 with a homologous point
mutation in transmembrane VI (LGR8 D637G) was generated. After
transfection of expression constructs encoding wild-type or mutant
receptors into 293T cells, basal cAMP levels were monitored.
Transfection of 293T cells with increasing concentrations (0-500
ng/well) of expression vectors encoding LGR8 D647Y, LGR7(1) D637Y
and LH receptor D578Y led to increases in basal cAMP levels in
transfected cells. In contrast, cAMP levels in cells transfected
with wild-type (WT) receptors were negligible (n=3;
mean.+-.SE).
[0009] FIG. 2. LGR7 and LGR8 are relaxin receptors. Porcine relaxin
stimulated cAMP production by 293T cells expressing recombinant
LGR7 (A) and LGR8 (B). Relaxin, but not insulin, IGF-1, or IGF-II
does-dependently increased the cAMP production by 293T cells
overexpressing recombinant receptors. In addition, glucagon, a
Gs-coupled receptor activator, also has no effect on cAMP
production by LGR7 and LGR8. Although there are two splicing
variants for human LGR7 (Hsu et al. (2000) Mol Endocrinol.
14(8):1257-71), the long form was used exclusively for the present
analysis.
[0010] FIG. 3. Tissue distribution of LGR7 and LGR8. A) Profiles of
LGR7 and LGR8 transcripts in human tissues. PCR analyses of LGR7
and LGR8 in diverse human tissues were conducted using human cDNA
from ovary, testis, kidney, thyroid, spleen, brain, pancreas,
pituitary, uterus, prostate, heart, hypothalamus, placenta, and
lymph nodes (1 ug/reaction) and LGR gene-specific primer pairs
under high-stringency conditions. Specific bands are indicated by
arrowheads. PCR amplification was carried out under high stringency
conditions to minimize nonspecific signals (denaturation: 94C, 30
sec, annealing and extension: 68-72C, 3 min; 35 cycles). B)
Immunohistochemical analysis of LGR7 expression in rodent
reproductive tracts. Specific LGR7 staining in uterus, cervix,
mammary gland, and pituitary were indicated by black arrowheads.
Epithelial layer (EL); stromal layer (SL); Muscularis layer (ML);
mammary gland and nipple, anterior pituitary, intestine, skin, etc.
Staining using control antiserum showed negligible signals.
[0011] FIG. 4. Neutralization of relaxin actions using the ligand
binding domain of LGR7. A) Generation of the soluble ectodomain of
LGR7 (7BP) using an anchored receptor approach. Permanent 293T cell
lines overexpressing 7BP-CD8 were cultured under serum-free
conditioned and treated with thrombin for three days, and soluble
recombinant 7BP tagged with 6-His and M1 epitopes was purified
using Nickel and anti-FLAG affinity chromatography under natural
conditions. Specific 7BP bands following Western blotting analysis
using M1-FLAG antibody was indicated by an arrowhead (lane B).
Homologous domain of LGR4 (4BP) was also generated using the same
approach and shown on lane C. B) Specific interaction of relaxin
and 7BP. Purified porcine relaxin was incubated with recombinant
7BP in PBS and crosslinked with disuccinimidyl suberat, before
boiling for 5 min. under denaturing conditions and resolved in 7.5%
SDS PAGE. The relaxin/7BP complex was detected by an anti-relaxin
antibody whereas 4BP showed negligible interaction with relaxin. C)
Recombinant 7BP blocked the stimulatory effects of relaxin on LGR7
and LGR8. 293T cells expressing LGR7 or LGR8 were treated with 0.1
nM relaxin in combination with different dosage of 7BP or 4BP for
24 h under serum-free conditions. D) Treatment of cultured rat
myometrial cells with 7BP blocked the relaxin stimulation of cAMP
production. Uterine tissues were obtained from 25-day-old female
rats implanted with diethystibestrol for 3 days. Myometrial cells
were prepared by serial digestions with trypsin and collegenase and
cultured. Cells were treated with 1 nM of porcine relaxin with or
without recombinant 7BP under serum-free conditions for 24 h.
[0012] FIG. 5. Activation of LGR8 but not LGR7 by INSL3. Cells
expressing recombinant human LGR8 or LGR7 were treated with INSL3
from different species, or with biotinylated-ovine INSL3
(Biotin-INSL3), porcine relaxin (RLX) or glucagon. Ligand signaling
was estimated based on extracellular cAMP production. A) LGR8. B)
LGR7.
[0013] FIG. 6. Direct binding of biotinylated INSL3 to LGR8. A)
Ligand binding assays. Cells expressing LGR8 were incubated with 5
nM of biotinylated ovine INSL3 with or without increasing levels of
rat INSL3. Specific INSL3 binding to LGR8 was estimated using
labeled strepavidin. B) Cross-linking of INSL3 to LGR8. Cells
expressing LGR8 were incubated with biotinylated INSL3
(Biotin-INSL3) with or without a 20-fold excess INSL3 before
cross-linking. Complexes of biotinylated INSL3 and LGR8 were
detected using the avidin-HRP following SDS-PAGE and protein
blotting. Lane 1, biotin-INSL3 alone; lane 2, INSL3-LGR8 complexes;
lane 3; competition with excess non-biotinylated INSL3; lane 4,
recombinant LGR8 detected using the M1 antibody.
[0014] FIG. 7. Expression of LGR8 transcripts in the gubernaculum
and INSL3 stimulation of cAMP production and thymidine
incorporation by cultured gubernacular cells. A) Northern blot
analyses. G: gubernaculum; D: diaphragm; T, testis. B) Stimulation
of cAMP production in primary cultures of gubernacular cells
treated with rat INSL3, porcine relaxin (RLX) or glucagon (Glu).
Some cells were treated with foskolin (FS) served as positive
controls whereas diaphragm muscle cells served as negative
controls. C) Stimulation of thymidine incorporation by cultured
gubernacular cells treated with different hormones for 24 h.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0015] High affinity relaxin receptors, polypeptide compositions
related thereto, as well as nucleotide compositions encoding the
same, are provided. The subject polypeptide and/or nucleic acid
compositions find use in a variety of different applications,
including the identification of homologous or related genes; for
the identification of endogenous ligands for these novel receptors;
the production of compositions that modulate the expression or
function of the receptors; for gene therapy; for mapping functional
regions of the receptors; in studying associated physiological
pathways; for in vivo prophylactic and therapeutic purposes; as
immunogens for producing antibodies; in screening for biologically
active agents; and the like.
[0016] Relaxin is a hormone with a number of important functions,
which include the modulation of the reproductive physiology of
human beings and other mammals, including, but not limited to,
maintaining pregnancy, effecting parturition, and enhancing sperm
motility as an aid in fertilization. Relaxin has significant
effects on connective tissue, as evidenced by its role in
pregnancy, for example on the pubic symphysis and rearrangement of
collagenous filaments effecting parturition; depressant effects on
the myometrium; preparation of the endometrium for implantation;
role in luteolysis; growth and differentiation of the mammary
glands; enhancement of sperm motility; and augmentation of the
ability of sperm to penetrate the human cervix. Relaxin has been
implicated in the dilation of cardiac and blood vessels' smooth
muscle cells, and has also been used in the treatment of severe
chronic pain, particularly pain arising from stretching, swelling,
or dislocation of tissues.
[0017] Human relaxin and its methods of preparation, including
synthesis in recombinant cell culture, are known. Included within
the scope of the term "relaxin" are human relaxins from recombinant
or native sources as well as relaxin variants, such as amino acid
sequence variants. The predominant species of human relaxin in the
corpus luteum and serum is the H2 relaxin form with a truncated B
chain, i.e., relaxin H2(B29 A24), wherein the four C-terminal amino
acids of the B-chain are absent. Also included within the scope of
the term "human relaxin" are other insertions, substitutions, or
deletions of one or more amino acid residues, glycosylation
variants, unglycosylated human relaxin, organic and inorganic
salts, covalently modified derivatives of human relaxin, human
preprorelaxin, and human prorelaxin.
[0018] Before the subject invention is further described, it is to
be understood that the invention is not limited to the particular
embodiments of the invention described below, as variations of the
particular embodiments may be made and still fall within the scope
of the appended claims. It is also to be understood that the
terminology employed is for the purpose of describing particular
embodiments, and is not intended to be limiting. Instead, the scope
of the present invention will be established by the appended
claims.
[0019] In this specification and the appended claims, the singular
forms "a," "an," and "the" include plural reference unless the
context clearly dictates otherwise. Unless defined otherwise, all
technical and scientific terms used herein have the same meaning as
commonly understood to one of ordinary skill in the art to which
this invention belongs.
Characterization of LGR7 and LRG8
[0020] LGR7 and LRG8 are mammalian high affinity relaxin receptors,
which are of the G-protein coupled, seven trans-membrane family of
proteins, specifically the subfamily of G-protein coupled seven
trans-membrane proteins that are characterized by the presence of
extra-cellular leucine rich repeat regions. LRG8 is novel; LRG7 is
described in co-pending patent application U.S. Ser. No.
09/647,067. These proteins have both a G-protein coupled seven
trans-membrane region and a leucine rich repeat extra-cellular
domain. Both of these receptors mediate the production of cAMP in
response to binding of relaxin, which production is inhibited by
the addition of anti-relaxin antibodies.
[0021] The human LGR7 gene encodes two splicing variants (see Hsu
et al. 2000), of 757 and 723 amino acids, respectively. These
molecules may be referred to as LGR7(1) and LGR7(2), respectively,
or generically as LGR7. LGR7 is expressed in multiple tissues,
including testis, ovary, prostate, intestine and colon. Expression
of LGR7 is cell type-specific in different rodent tissues. In the
uterus, the expression of LGR7 is mainly in the endometrial and
muscularis layers but minimal in stromal and interstitial cells,
consistent with the utero-muscular modulating activity of relaxin.
In the cervix, LGR7 was found in all muscularis layer. In contrast,
negligible staining is found in the skeletal muscle.
[0022] The sequence of LGR8 is provided as SEQ ID NO:1, and encodes
a polypeptide of 754 amino acids (SEQ ID NO:2). LGR8 is mainly
expressed in the brain, kidney, muscle, testis, thyroid, uterus,
bone marrow and peripheral blood cells. In addition to relaxin,
LGR8 is a receptor for INSL3, an insulin-like protein related to
relaxin (Adham et al. (1993) J. Biol. Chem. 268:26668-26672;
Burkhardt et al. (1994) Genomics 20: 13-19). InsL3, is expressed
exclusively in prenatal and postnatal Leydig cells. INSL3 has a
role in the development of the male urogenital tract and in female
fertility. Mutations in InsL3 are associated with
cryptorchidism.
[0023] Soluble fragments of LGR7 and LGR8 are constructed by
deletion of the transmembrane domain of the receptor. For example,
a soluble form of LGR7 is made by truncating the protein to delete
the transmembrane domain at L402. Gain of function mutations in
LGR7(1); LGR7(2) and LGR8 are made by amino acid substitution, for
example in the molecules LGR8 D647Y, and LGR7(1) D637Y. These
mutated receptors show increased basal levels of activity.
LGR7 and LGR8 Polypeptides
[0024] For use in the subject methods, either of the native LGR7 or
LGR8 forms, modifications thereof, or a combination of forms may be
used. Polypeptides of interest include the complete mature protein,
soluble fragments derived therefrom, relaxin-binding domains,
mutations which may be a gain of function or loss of function
mutation, and other derivatives and fragments thereof. A fragment
of a LGR7 or LGR8 peptide may be selected to achieve a specific
purpose, including solubility, isolation of specific domains and
binding regions, and the like. Fragments will usually comprise at
least about 10 amino acids of the provided amino acid sequences,
and comprise 25, 50, 100 or up to the complete polypeptide
sequence.
[0025] The sequence of the LGR7 or LGR8 polypeptide may be altered
in various ways known in the art to generate targeted changes in
sequence. The polypeptide will usually be substantially similar to
the sequences provided herein, i.e. will differ by at least one
amino acid, and may differ by at least two but not more than about
ten amino acids. The sequence changes may be substitutions,
insertions or deletions. Scanning mutations that systematically
introduce alanine, or other residues, may be used to determine key
amino acids. Conservative amino acid substitutions typically
include substitutions within the following groups: (glycine,
alanine); (valine, isoleucine, leucine); (aspartic acid, glutamic
acid); (asparagine, glutamine); (serine, threonine); (lysine,
arginine); or (phenylalanine, tyrosine).
[0026] Modifications of interest that do not alter primary sequence
include chemical derivatization of polypeptides, e.g., acetylation,
or carboxylation. Also included are modifications of glycosylation,
e.g. those made by modifying the glycosylation patterns of a
polypeptide during its synthesis and processing or in further
processing steps; e.g. by exposing the polypeptide to enzymes which
affect glycosylation, such as mammalian glycosylating or
deglycosylating enzymes. Also embraced are sequences that have
phosphorylated amino acid residues, e.g. phosphotyrosine,
phosphoserine, or phosphothreonine.
[0027] Also included in the subject invention are polypeptides that
have been modified using ordinary molecular biological techniques
and synthetic chemistry so as to improve their resistance to
proteolytic degradation or to optimize solubility properties or to
render them more suitable as a therapeutic agent. For examples, the
backbone of the peptide may be cyclized to enhance stability (see
Friedler et al. (2000) J. Biol. Chem. 275:23783-23789). Analogs of
such polypeptides include those containing residues other than
naturally occurring L-amino acids, e.g. D-amino acids or
non-naturally occurring synthetic amino acids.
[0028] The subject peptides may be prepared by in vitro synthesis,
using conventional methods as known in the art. Various commercial
synthetic apparatuses are available, for example automated
synthesizers by Applied Biosystems Inc., Foster City, Calif.,
Beckman, etc. By using synthesizers, naturally occurring amino
acids may be substituted with unnatural amino acids. The particular
sequence and the manner of preparation will be determined by
convenience, economics, purity required, and the like.
[0029] If desired, various groups may be introduced into the
peptide during synthesis or during expression, which allow for
linking to other molecules or to a surface. Thus cysteines can be
used to make thioethers, histidines for linking to a metal ion
complex, carboxyl groups for forming amides or esters, amino groups
for forming amides, and the like.
[0030] The polypeptides may also be isolated and purified in
accordance with conventional methods of recombinant synthesis. A
lysate may be prepared of the expression host and the lysate
purified using HPLC, exclusion chromatography, gel electrophoresis,
affinity chromatography, or other purification technique. For the
most part, the compositions which are used will comprise at least
20% by weight of the desired product, more usually at least about
75% by weight, preferably at least about 95% by weight, and for
therapeutic purposes, usually at least about 99.5% by weight, in
relation to contaminants related to the method of preparation of
the product and its purification. Usually, the percentages will be
based upon total protein.
Compound Screening
[0031] The availability of purified LGR7 or LGR8 and other
components in the signaling pathways, e.g. relaxin, InsL3, altered
copies of these molecules, etc., allows in vitro reconstruction of
the signaling pathway. Two or more of the components may be
combined in vitro, and the behavior assessed in terms of production
of cAMP; modification of protein components, e.g. connective
tissues; ability of different protein components to bind to each
other etc. The components may be modified by sequence deletion,
substitution, etc. to determine the functional role of specific
residues.
[0032] Drug screening may be performed using an in vitro model, a
genetically altered cell or animal, or purified LGR7 or LGR8
protein. One can identify ligands or substrates that compete with,
modulate or mimic the action of LGR7 or LGR8. Areas of
investigation include the development of treatments for altering
connective tissue, which may be in connection with pregnancy and
birth, with disease states such as scleroderma and fibromyalgia,
with the treatment of pain associated with distortions in
connective tissue; with the treatment of cryptorchidism; the
treatment of endometriosis; the relaxation of smooth muscle cells;
and the like.
[0033] Drug screening identifies agents that mimic LGR7 or LGR8
activity, either as an antagonist or as an agonist. A wide variety
of assays may be used for this purpose, including labeled in vitro
protein-protein binding assays, electrophoretic mobility shift
assays, immunoassays for protein binding, and the like. Knowledge
of the 3-dimensional structure of LGR7 or LGR8, derived from
crystallization of purified synthetic LGR7 or LGR8 protein, leads
to the rational design of small drugs that specifically inhibit
LGR7 or LGR8 activity.
[0034] The term "agent" as used herein describes any molecule, e.g.
protein or pharmaceutical, with the capability of altering or
mimicking the physiological function of LGR7 or LGR8. Generally a
plurality of assay mixtures are run in parallel with different
agent concentrations to obtain a differential response to the
various concentrations. Typically one of these concentrations
serves as a negative control, i.e. at zero concentration or below
the level of detection.
[0035] Candidate agents encompass numerous chemical classes, though
typically they are organic molecules, preferably small organic
compounds having a molecular weight of more than 50 and less than
about 2,500 daltons. Candidate agents comprise functional groups
necessary for structural interaction with proteins, particularly
hydrogen bonding, and typically include at least an amine,
carbonyl, hydroxyl or carboxyl group, preferably at least two of
the functional chemical groups. The candidate agents often comprise
cyclical carbon or heterocyclic structures and/or aromatic or
polyaromatic structures substituted with one or more of the above
functional groups. Candidate agents are also found among
biomolecules including peptides, saccharides, fatty acids,
steroids, purines, pyrimidines, derivatives, structural analogs or
combinations thereof.
[0036] Candidate agents are obtained from a wide variety of sources
including libraries of synthetic or natural compounds. For example,
numerous means are available for random and directed synthesis of a
wide variety of organic compounds and biomolecules, including
expression of randomized oligonucleotides and oligopeptides.
Alternatively, libraries of natural compounds in the form of
bacterial, fungal, plant and animal extracts are available or
readily produced. Additionally, natural or synthetically produced
libraries and compounds are readily modified through conventional
chemical, physical and biochemical means, and may be used to
produce combinatorial libraries. Known pharmacological agents may
be subjected to directed or random chemical modifications, such as
acylation, alkylation, esterification, amidification, etc. to
produce structural analogs.
[0037] Where the screening assay is a binding assay, one or more of
the molecules may be joined to a label, where the label can
directly or indirectly provide a detectable signal. Various labels
include radioisotopes, fluorescers, chemiluminescers, enzymes,
specific binding molecules, particles, e.g. magnetic particles, and
the like. Specific binding molecules include pairs, such as biotin
and streptavidin, digoxin and antidigoxin, etc. For the specific
binding members, the complementary member would normally be labeled
with a molecule that provides for detection, in accordance with
known procedures.
[0038] A variety of other reagents may be included in the screening
assay. These include reagents like salts, neutral proteins, e.g.
albumin, detergents, etc that are used to facilitate optimal
protein-protein binding and/or reduce non-specific or background
interactions. Reagents that improve the efficiency of the assay,
such as protease inhibitors, nuclease inhibitors, anti-microbial
agents, etc. may be used. The mixture of components are added in
any order that provides for the requisite binding. Incubations are
performed at any suitable temperature, typically between 4 and
40.degree. C. Incubation periods are selected for optimum activity,
but may also be optimized to facilitate rapid high-throughput
screening. Typically between 0.1 and 1 hours will be
sufficient.
[0039] Relaxin or analogs thereof may be useful in the screening
assays, as competitors, controls, in structural studies of binding
sites, etc. A number of such molecules have been described, for
example, see U.S. Pat. Nos. 6,200,953; 5,326,694; 5,320,953;
5,179,195; 5,145,962; 5,053,488; 5,023,321; 4,871,670; 4,758,516;
and 4,656,249.
[0040] The compounds having the desired pharmacological activity
may be administered in a physiologically acceptable carrier to a
host for treatment of connective tissue disorders, during pregnancy
etc. The compounds may be administered in a variety of ways,
orally, topically, parenterally e.g. subcutaneously,
intraperitoneally, by viral infection, intravascularly, etc.
Depending upon the manner of introduction, the compounds may be
formulated in a variety of ways. The concentration of
therapeutically active compound in the formulation may vary from
about 0.1-10 wt %.
Antibodies Specific for LGR7 or LGR8 Polypeptides
[0041] The present invention provides antibodies specific for LGR7
or LGR8 polypeptides, e.g. any one of the variants, polypeptides,
or domains described above. Such antibodies are useful, for
example, in methods of detecting the presence of LGR7 or LGR8 in a
biological sample, and in methods of isolating LGR7 or LGR8 from a
biological sample.
[0042] The LGR7 or LGR8 polypeptides of the invention are useful
for the production of antibodies, where short fragments provide for
antibodies specific for the particular polypeptide, and larger
fragments or the entire protein allow for the production of
antibodies over the surface of the polypeptide. As used herein, the
term "antibodies" includes antibodies of any isotype, fragments of
antibodies which retain specific binding to antigen, including, but
not limited to, Fab, Fv, scFv, and Fd fragments, chimeric
antibodies, humanized antibodies, single-chain antibodies, and
fusion proteins comprising an antigen-binding portion of an
antibody and a non-antibody protein. The antibodies may be
detectably labeled, e.g., with a radioisotope, an enzyme which
generates a detectable product, a green fluorescent protein, and
the like. The antibodies may be further conjugated to other
moieties, such as members of specific binding pairs, e.g., biotin
(member of biotin-avidin specific binding pair), and the like. The
antibodies may also be bound to a solid support, including, but not
limited to, polystyrene plates or beads, and the like.
[0043] "Antibody specificity", in the context of antibody-antigen
interactions, is a term well understood in the art, and indicates
that a given antibody binds to a given antigen, wherein the binding
can be inhibited by that antigen or an epitope thereof which is
recognized by the antibody, and does not substantially bind to
unrelated antigens. Methods of determining specific antibody
binding are well known to those skilled in the art, and can be used
to determine the specificity of antibodies of the invention for a
LGR7 or LGR8 polypeptide, particularly a human LGR7 or LGR8
polypeptide.
[0044] Antibodies are prepared in accordance with conventional
ways, where the expressed polypeptide or protein is used as an
immunogen, by itself or conjugated to known immunogenic carriers,
e.g. KLH, pre-S HBsAg, other viral or eukaryotic proteins, or the
like. Various adjuvants may be employed, with a series of
injections, as appropriate. For monoclonal antibodies, after one or
more booster injections, the spleen is isolated, the lymphocytes
immortalized by cell fusion, and then screened for high affinity
antibody binding. The immortalized cells, i.e. hybridomas,
producing the desired antibodies may then be expanded. For further
description, see Monoclonal Antibodies: A Laboratory Manual, Harlow
and Lane eds., Cold Spring Harbor Laboratories, Cold Spring Harbor,
N.Y., 1988. If desired, the mRNA encoding the heavy and light
chains may be isolated and mutagenized by cloning in E. coli, and
the heavy and light chains mixed to further enhance the affinity of
the antibody. Alternatives to in vivo immunization as a method of
raising antibodies include binding to phage display libraries,
usually in conjunction with in vitro affinity maturation.
Uses of LGR7 or LGR8 Agonists and Antagonists
[0045] As receptors for relaxin and InsL3, LGR7 and LGR8 have
important roles in the physiology of pregnancy, reproductive
development, other biological processes relating to smooth muscle
and to connective tissue; and the like. Formulations of LGR8 or
LGR9, particularly the soluble receptor, as well as other agents
that act as agonists or antagonists of these receptors find
clinical use.
[0046] Agonists or other molecules that simulate the effect of
relaxin affect epithelial cells, blood vessels, stromal cells
(putative fibroblasts), and smooth muscle in the cervix and vagina,
e.g. by promoting the onset of labor, increasing endometrial cells,
inducing synthesis of mucins, regulating pituitary prolactin,
oxytocin, and vasopressin release, etc.
[0047] These molecules also have important effects on the vascular
system. Agonists, such as relaxin, are angiogenic in the
endometrial lining, and plays a role in the attachment of the
embryo to the uterus. They can be administered to increase blood
flow and vasodilation of vascular beds. Methods for the use of
relaxin to increase angiogenesis are described in U.S. Pat. No.
6,211,147. Relaxin and other agonists can act as a factor in
protection against arteriosclerosis and ischemic or thrombotic
pathologies, by inducing dilation of blood vessels' smooth muscle
cells which results in an increment of blood flow; inhibits
coagulation processes, intensifies the fibrinolysis and lowers
blood concentration of lipids and sodium. This effect is mediated
both directly, and through release NO and ANP, which largely
contribute to the effect on vessel walls and blood components. See,
for example, U.S. Pat. No. 5,952,296.
[0048] Agonists also act as an anti-fibrinolytic agent by
decreasing collagen production, increasing collagen breakdown, and
reducing the production of the collagenase inhibitor, TIMP Agonists
may act directly on stromal cells to promote remodeling of the
extracellular matrix.
[0049] Agonist-induced remodeling of connective tissue has
potential for clinical applications, for example in the treatment
of systemic sclerosis, or scleroderma, and as a cervical softening
agent at term. Conversely, antagonists of LGR7 or LGR8 find use in
the prevention of labor, for example to inhibit pre-term labor.
[0050] Agonists of LGR7 or LGR8 also find use in the treatment of
fibromyalgia, and may also include the treatment of neurological
disorders, for example Alzheimer's disease, Parkinson's, and/or
other conditions such as ADD.
[0051] Another use of the LGR7 or LGR8 agonists is as an analgesic
and palliative for intractable pain (see U.S. Pat. No. 5,656,592).
Although relaxin and other agonists can be used generally as an
analgesic and palliative for pain, the conditions most amenable to
its therapeutic administration are those in which unusual stress is
chronically placed on tissues because of an acquired or inherent
malformation which results in the displacement of tissues from
their natural disposition in the body. These agents finds utility,
for example, in the treatment of severe chronic pain, particularly
pain arising from stretching, swelling, or dislocation of
tissues.
[0052] Agonists of LGR8 in particular find use in the treatment of
cryptorchidism, a condition that is related to the ligand of LGR8,
InsL3. The term cryptorchidism indicates a testis, which has failed
to descend to the scrotum and is located at any point along the
normal path of descent or at an ectopic site. Hormones play a
pivotal role in testicular descent except during the migration to
the level of internal inguinal ring. Cryptorchidism is present in
about 4.5% of newborns with a higher incidence in preterms. The
incidence decreases to 1.2% by the first year. It is classified as
palpable and impalpable. The most common site of an ectopic testis
is superficial inguinal pouch. Retractile testis is often bilateral
and most common in boys between 5 and 6 years of age. Hypospadias
and inguinal hernias are the most common associated anomalies seen
with undescended testis. Common complications include torsion and
atrophy of testis. Infertility is seen in about 40% of unilateral
and 70% of bilateral cryptorchidism. Undescended testis is 20 to 40
times more likely to undergo malignant transformation than normal
testis.
Formulations
[0053] The compounds of this invention can be incorporated into a
variety of formulations for therapeutic administration.
Particularly, agents specifically bind to and activate LGR7 or
LGR8; agents that block binding of native ligands, e.g. relaxin or
InsL3, to LGR7 or LGR8; agents that modulate expression of LGR7 or
LGR8; LGR7 or LGR8 polypeptides and analogs or fragments thereof;
etc., are formulated for administration to patients for various
clinical purposes, as previously described. More particularly, the
compounds of the present invention can be formulated into
pharmaceutical compositions by combination with appropriate,
pharmaceutically acceptable carriers or diluents, and may be
formulated into preparations in solid, semi-solid, liquid or
gaseous forms, such as tablets, capsules, powders, granules,
ointments, solutions, suppositories, injections, inhalants, gels,
microspheres, and aerosols. As such, administration of the
compounds can be achieved in various ways, including oral, buccal,
rectal, parenteral, intraperitoneal, intradermal, transdermal,
intracheal, etc., administration. The agents may be systemic after
administration or may be localized by the use of an implant that
acts to retain the active dose at the site of implantation.
[0054] In pharmaceutical dosage forms, the compounds may be
administered in the form of their pharmaceutically acceptable
salts, or they may also be used alone or in appropriate
association, as well as in combination with other pharmaceutically
active compounds. The following methods and excipients are merely
exemplary and are in no way limiting.
[0055] For oral preparations, the compounds can be used alone or in
combination with appropriate additives to make tablets, powders,
granules or capsules, for example, with conventional additives,
such as lactose, mannitol, corn starch or potato starch; with
binders, such as crystalline cellulose, cellulose derivatives,
acacia, corn starch or gelatins; with disintegrators, such as corn
starch, potato starch or sodium carboxymethylcellulose; with
lubricants, such as talc or magnesium stearate; and if desired,
with diluents, buffering agents, moistening agents, preservatives
and flavoring agents.
[0056] The compounds can be formulated into preparations for
injections by dissolving, suspending or emulsifying them in an
aqueous or nonaqueous solvent, such as vegetable or other similar
oils, synthetic aliphatic acid glycerides, esters of higher
aliphatic acids or propylene glycol; and if desired, with
conventional additives such as solubilizers, isotonic agents,
suspending agents, emulsifying agents, stabilizers and
preservatives.
[0057] The compounds can be utilized in aerosol formulation to be
administered via inhalation. The compounds of the present invention
can be formulated into pressurized acceptable propellants such as
dichlorodifluoromethane, propane, nitrogen and the like.
[0058] Furthermore, the compounds can be made into suppositories by
mixing with a variety of bases such as emulsifying bases or
water-soluble bases. The compounds of the present invention can be
administered rectally via a suppository. The suppository can
include vehicles such as cocoa butter, carbowaxes and polyethylene
glycols, which melt at body temperature, yet are solidified at room
temperature.
[0059] Unit dosage forms for oral or rectal administration such as
syrups, elixirs, and suspensions may be provided wherein each
dosage unit, for example, teaspoonful, tablespoonful, tablet or
suppository, contains a predetermined amount of the composition
containing one or more compounds of the present invention.
Similarly, unit dosage forms for injection or intravenous
administration may comprise the compound of the present invention
in a composition as a solution in sterile water, normal saline or
another pharmaceutically acceptable carrier.
[0060] Implants for sustained release formulations are well-known
in the art. Implants are formulated as microspheres, slabs, etc.
with biodegradable or non-biodegradable polymers. For example,
polymers of lactic acid and/or glycolic acid form an erodible
polymer that is well-tolerated by the host. The implant is placed
in proximity to the targeted site, so that the local concentration
of active agent is increased relative to the rest of the body.
[0061] The term "unit dosage form," as used herein, refers to
physically discrete units suitable as unitary dosages for human and
animal subjects, each unit containing a predetermined quantity of
compounds of the present invention calculated in an amount
sufficient to produce the desired effect in association with a
pharmaceutically acceptable diluent, carrier or vehicle. The
specifications for the novel unit dosage forms of the present
invention depend on the particular compound employed and the effect
to be achieved, and the pharmacodynamics associated with each
compound in the host.
[0062] The pharmaceutically acceptable excipients, such as
vehicles, adjuvants, carriers or diluents, are readily available to
the public. Moreover, pharmaceutically acceptable auxiliary
substances, such as pH adjusting and buffering agents, tonicity
adjusting agents, stabilizers, wetting agents and the like, are
readily available to the public.
[0063] Typical dosages for systemic administration range from 0.1
.mu.g to 100 milligrams per kg weight of subject per
administration. A typical dosage may be one tablet taken from two
to six times daily, or one time-release capsule or tablet taken
once a day and containing a proportionally higher content of active
ingredient. The time-release effect may be obtained by capsule
materials that dissolve at different pH values, by capsules that
release slowly by osmotic pressure, or by any other known means of
controlled release.
[0064] Those of skill will readily appreciate that dose levels can
vary as a function of the specific compound, the severity of the
symptoms and the susceptibility of the subject to side effects.
Some of the specific compounds are more potent than others.
Preferred dosages for a given compound are readily determinable by
those of skill in the art by a variety of means. A preferred means
is to measure the physiological potency of a given compound.
[0065] The use of liposomes as a delivery vehicle is one method of
interest. The liposomes fuse with the cells of the target site and
deliver the contents of the lumen intracellularly. The liposomes
are maintained in contact with the cells for sufficient time for
fusion, using various means to maintain contact, such as isolation,
binding agents, and the like. In one aspect of the invention,
liposomes are designed to be aerosolized for pulmonary
administration. Liposomes may be prepared with purified proteins or
peptides that mediate fusion of membranes, such as Sendai virus or
influenza virus, etc. The lipids may be any useful combination of
known liposome forming lipids, including cationic lipids, such as
phosphatidylcholine. The remaining lipid will normally be neutral
lipids, such as cholesterol, phosphatidyl serine, phosphatidyl
glycerol, and the like.
LGR7 or LGR8 Nucleic Acids
[0066] The invention includes novel nucleic acids having a sequence
set forth in SEQ ID NO:1; nucleic acids that hybridize under
stringent conditions, particularly conditions of high stringency,
to the sequence set forth in SEQ ID NO:1; genes corresponding to
the provided nucleic acids; sequences encoding the polypeptide set
forth in SEQ ID NO:2 (LGR8); and fragments and derivatives
thereof.
[0067] The nucleic acids of the invention include nucleic acids
having sequence similarity or sequence identity to SEQ ID NO:1.
Nucleic acids having sequence similarity are detected by
hybridization under low stringency conditions, for example, at
50.degree. C. and 10.times.SSC (0.9 M saline/0.09 M sodium citrate)
and remain bound when subjected to washing at 55.degree. C. in
1.times.SSC. Sequence identity can be determined by hybridization
under stringent conditions, for example, at 50.degree. C. or higher
and 0.1.times.SSC (9 mM saline/0.9 mM sodium citrate).
Hybridization methods and conditions are well known in the art,
see, e.g., U.S. Pat. No. 5,707,829. Nucleic acids that are
substantially identical to the provided nucleic acid sequence, e.g.
allelic variants, genetically altered versions of the gene, etc.,
bind to SEQ ID NO:1 under stringent hybridization conditions. By
using probes, particularly labeled probes of DNA sequences, one can
isolate homologous or related genes. The source of homologous genes
can be any species, e.g. primate species, particularly human;
rodents, such as rats and mice; canines, felines, bovines, ovines,
equines, fish, yeast, nematodes, etc.
[0068] In one embodiment, hybridization is performed using at least
18 contiguous nucleotides (nt) of SEQ ID NO:1 or a DNA encoding the
polypeptide of SEQ ID NO:2. Such a probe will preferentially
hybridize with a nucleic acid comprising the complementary
sequence, allowing the identification and retrieval of the nucleic
acids that uniquely hybridize to the selected probe. Probes of more
than 18 nt can be used, e.g., probes of from about 18 nt to about
25, 50, 100, 250, or 500 nt, but 18 nt usually represents
sufficient sequence for unique identification.
[0069] Nucleic acids of the invention also include naturally
occurring and synthetically produced variants of the nucleotide
sequences (e.g., degenerate variants, gain of function mutations,
soluble forms, allelic variants, etc.). Variants of the nucleic
acids of the invention are identified by hybridization of putative
variants with nucleotide sequences disclosed herein, preferably by
hybridization under stringent conditions. For example, by using
appropriate wash conditions, variants of the nucleic acids of the
invention can be identified where the allelic variant exhibits at
most about 25-30% base pair (bp) mismatches relative to the
selected nucleic acid probe. In general, allelic variants contain
15-25% bp mismatches, and can contain as little as even 5-15%, or
2-5%, or 1-2% bp mismatches, as well as a single bp mismatch.
[0070] The invention also encompasses homologs corresponding to the
nucleic acids of SEQ ID NO:1 or a DNA encoding the polypeptide of
SEQ ID NO:2, where the source of homologous genes can be any
mammalian species, e.g., primate species, particularly human;
rodents, such as rats; canines, felines, bovines, ovines, equines,
fish, yeast, nematodes, etc. Between mammalian species, e.g., human
and mouse, homologs generally have substantial sequence similarity,
e.g., at least 75% sequence identity, usually at least 90%, more
usually at least 95% between nucleotide sequences. Sequence
similarity is calculated based on a reference sequence, which may
be a subset of a larger sequence, such as a conserved motif, coding
region, flanking region, etc. A reference sequence will usually be
at least about 18 contiguous nt long, more usually at least about
30 nt long, and may extend to the complete sequence that is being
compared. Algorithms for sequence analysis are known in the art,
such as gapped BLAST, described in Altschul, et al. Nucleic Acids
Res. (1997) 25:3389-3402.
[0071] The subject nucleic acids can be cDNAs or genomic DNAs, as
well as fragments thereof, particularly fragments that encode a
biologically active polypeptide and/or are useful in the methods
disclosed herein (e.g., in diagnosis, as a unique identifier of a
differentially expressed gene of interest, etc.) The term "cDNA" as
used herein is intended to include all nucleic acids that share the
arrangement of sequence elements found in native mature mRNA
species, where sequence elements are exons and 3' and 5' non-coding
regions. Normally mRNA species have contiguous exons, with the
intervening introns, when present, being removed by nuclear RNA
splicing, to create a continuous open reading frame encoding a
polypeptide of the invention.
[0072] A genomic sequence of interest comprises the nucleic acid
present between the initiation codon and the stop codon, as defined
in the listed sequences, including all of the introns that are
normally present in a native chromosome. It can further include the
3' and 5' untranslated regions found in the mature mRNA. It can
further include specific transcriptional and translational
regulatory sequences, such as promoters, enhancers, etc., including
about 1 kb, but possibly more, of flanking genomic DNA at either
the 5' and 3' end of the transcribed region. The genomic DNA can be
isolated as a fragment of 100 kbp or smaller; and substantially
free of flanking chromosomal sequence. The genomic DNA flanking the
coding region, either 3' and 5', or internal regulatory sequences
as sometimes found in introns, contains sequences required for
proper tissue, stage-specific, or disease-state specific
expression.
[0073] The nucleic acid compositions of the subject invention can
encode all or a part of the subject polypeptides. Double or single
stranded fragments can be obtained from the DNA sequence by
chemically synthesizing oligonucleotides in accordance with
conventional methods, by restriction enzyme digestion, by PCR
amplification, etc. Isolated nucleic acids and nucleic acid
fragments of the invention comprise at least about 18, about 50,
about 100, to about 500 contiguous nt selected from the nucleic
acid sequence as shown in SEQ ID NO:1. For the most part, fragments
will be of at least 18 nt, usually at least 25 nt, and up to at
least about 50 contiguous nt in length or more.
[0074] Probes specific to the nucleic acid of the invention can be
generated using the nucleic acid sequence disclosed in SEQ ID NO:1
or a DNA encoding the polypeptide of SEQ ID NO:2. The probes are
preferably at least about 18 nt, 25nt or more of the corresponding
contiguous sequence. The probes can be synthesized chemically or
can be generated from longer nucleic acids using restriction
enzymes. The probes can be labeled, for example, with a
radioactive, biotinylated, or fluorescent tag. Preferably, probes
are designed based upon an identifying sequence of one of the
provided sequences. More preferably, probes are designed based on a
contiguous sequence of one of the subject nucleic acids that remain
unmasked following application of a masking program for masking low
complexity (e.g., BLASTX) to the sequence., i.e., one would select
an unmasked region, as indicated by the nucleic acids outside the
poly-n stretches of the masked sequence produced by the masking
program.
[0075] The nucleic acids of the subject invention are isolated and
obtained in substantial purity, generally as other than an intact
chromosome. Usually, the nucleic acids, either as DNA or RNA, will
be obtained substantially free of other naturally-occurring nucleic
acid sequences, generally being at least about 50%, usually at
least about 90% pure and are typically "recombinant," e.g., flanked
by one or more nucleotides with which it is not normally associated
on a naturally occurring chromosome.
[0076] The nucleic acids of the invention can be provided as a
linear molecule or within a circular molecule, and can be provided
within autonomously replicating molecules (vectors) or within
molecules without replication sequences. Expression of the nucleic
acids can be regulated by their own or by other regulatory
sequences known in the art. The nucleic acids of the invention can
be introduced into suitable host cells using a variety of
techniques available in the art, such as transferrin
polycation-mediated DNA transfer, transfection with naked or
encapsulated nucleic acids, liposome-mediated DNA transfer,
intracellular transportation of DNA-coated latex beads, protoplast
fusion, viral infection, electroporation, gene gun, calcium
phosphate-mediated transfection, and the like.
Modulation of LGR7 or LGR8 Activity
[0077] The LGR7 or LGR8 genes, gene fragments, or the encoded
protein or protein fragments are useful in gene therapy to treat
conditions associated with LGR7 or LGR8 activity. Inhibition is
achieved in a number of ways. Antisense or siRNA LGR7 or LGR8
sequences may be administered to inhibit expression. Competitive
binding antagonists, for example, a polypeptide that mimics LGR7 or
LGR8 binding may be used to inhibit activity. Other inhibitors are
identified by screening for biological activity in an LGR7 or LGR8
based binding assay. Upregulating activity is also of interest, for
example through the introduction of mutations have a gain of
function mutation, through increasing expression levels, and
through administering agents that bind to and activate LGR7 or
LGR8.
[0078] Expression vectors may be used to introduce the LGR7 or LGR8
gene into a cell. Such vectors generally have convenient
restriction sites located near the promoter sequence to provide for
the insertion of nucleic acid sequences. Transcription cassettes
may be prepared comprising a transcription initiation region, the
target gene or fragment thereof, and a transcriptional termination
region. The transcription cassettes may be introduced into a
variety of vectors, e.g. plasmid; retrovirus, e.g. lentivirus;
adenovirus; and the like, where the vectors are able to transiently
or stably be maintained in the cells, usually for a period of at
least about one day, more usually for a period of at least about
several days to several weeks.
[0079] The gene or LGR7 or LGR8 peptide may be introduced into
tissues or host cells by any number of routes, including viral
infection, microinjection, or fusion of vesicles. Jet injection may
also be used for intramuscular administration, as described by
Furth et al. (1992) Anal Biochem 205:365-368. The DNA may be coated
onto gold microparticles, and delivered intradermally by a particle
bombardment device, or "gene gun" as described in the literature
(see, for example, Tang et al. (1992) Nature 356:152-154), where
gold microprojectiles are coated with the LGR7 or LGR8 or DNA, then
bombarded into skin cells.
[0080] Antisense molecules can be used to down-regulate expression
of LGR7 or LGR8 in cells. The anti-sense reagent may be antisense
oligonucleotides (ODN), particularly synthetic ODN having chemical
modifications from native nucleic acids, or nucleic acid constructs
that express such anti-sense molecules as RNA. The antisense
sequence is complementary to the mRNA of the targeted gene, and
inhibits expression of the targeted gene products. Antisense
molecules inhibit gene expression through various mechanisms, e.g.
by reducing the amount of mRNA available for translation, through
activation of RNAse H, or steric hindrance. One or a combination of
such molecules may be administered, where a combination may
comprise multiple different sequences.
[0081] Antisense molecules may be produced by expression of all or
a part of the target gene sequence in an appropriate vector, where
the transcriptional initiation is oriented such that an antisense
strand is produced as an RNA molecule. Alternatively, the antisense
molecule is a synthetic oligonucleotide. Antisense oligonucleotides
will generally be at least about 7, usually at least about 12, more
usually at least about 20 nucleotides in length, and not more than
about 500, usually not more than about 50, more usually not more
than about 35 nucleotides in length, where the length is governed
by efficiency of inhibition, specificity, including absence of
cross-reactivity, and the like. It has been found that short
oligonucleotides, of from 7 to 8 bases in length, can be strong and
selective inhibitors of gene expression (see Wagner et al. (1996)
Nature Biotechnology 14:840-844).
[0082] In addition to antisense, small interfering RNA (siRNA)
duplexes can be used to inhibit expression of jeb genes. siRNA are
double stranded RNA molecules of at least about 18 nucleotides, and
may be up to the length of the complete mRNA. Preferred siRNA for
use in mammalian cells are from about 18 to 30 nucleotides,
preferably from about 21 to 22 nucleotides in length. For example,
see Elbashir et al. (2001) Nature 411:494-498.
[0083] Antisense oligonucleotides may be chemically synthesized by
methods known in the art (see Wagner et al. (1993) supra. and
Milligan et al., supra.) Preferred oligonucleotides are chemically
modified from the native phosphodiester structure, in order to
increase their intracellular stability and binding affinity. A
number of such modifications have been described in the literature,
which alter the chemistry of the backbone, sugars, heterocyclic
bases, morpholino derivatives, and the like.
[0084] Agents that block LGR7 or LGR8 activity provide a point of
intervention in an important signaling pathway. Numerous agents are
useful in reducing LGR7 or LGR8 activity, including agents that
directly modulate LGR7 or LGR8 expression as described above, e.g.
expression vectors, anti-sense specific for LGR7 or LGR8; and
agents that act on the LGR7 or LGR8 protein, e.g. LGR7 or LGR8
specific antibodies and analogs thereof, small organic molecules
that block LGR7 or LGR8 binding activity, etc.
Diagnostic Uses
[0085] Polynucleotide-based reagents derived from the sequence of
LGR7 or LGR8, e.g. PCR primers, oligonucleotide or cDNA probes, as
well as antibodies against LGR7 or LGR8s, are used to screen
patient samples, e.g. biopsy-derived tissues, amniotic fluid
samples, blood samples, etc., for increased expression of LGR7 or
LGR8 mRNA or proteins. DNA-based reagents are also designed for
evaluation of chromosomal loci implicated in certain diseases e.g.
for use in loss-of-heterozygosity (LOH) studies, or design of
primers based on LGR7 or LGR8 coding sequence. Of particular
interest is the use of LGR8 for genetic studies related to the
diagnosis of cryptorchidism, which is associated with the
expression of InsL3, and it's activation of LGR8.
[0086] The polynucleotides of the invention can be used to detect
differences in expression levels between two samples. A difference
between the protein levels, or the mRNA in the two tissues which
are compared, for example, in molecular weight, amino acid or
nucleotide sequence, or relative abundance, indicates a change in
the gene, or a gene which regulates it, in the tissue or cell
sample.
[0087] The subject nucleic acid and/or polypeptide compositions may
be used to analyze a patient sample for the presence of
polymorphisms associated with a disease state or genetic
predisposition to a disease state. Biochemical studies may be
performed to determine whether a sequence polymorphism in an LGR7
or LGR8 coding region or control regions is associated with
disease. Disease associated polymorphisms may include deletion or
truncation of the gene, mutations that alter expression level, that
affect the binding activity of the protein, the G protein activity,
etc.
[0088] Changes in the promoter or enhancer sequence that may affect
expression levels of LGR7 or LGR8 can be compared to expression
levels of the normal allele by various methods known in the art.
Methods for determining promoter or enhancer strength include
quantitation of the expressed natural protein; insertion of the
variant control element into a vector with a reporter gene such as
.beta.-galactosidase, luciferase, chloramphenicol
acetyltransferase, etc. that provides for convenient quantitation;
and the like.
[0089] A number of methods are available for analyzing nucleic
acids for the presence of a specific sequence, e.g. a disease
associated polymorphism. Where large amounts of DNA are available,
genomic DNA is used directly. Alternatively, the region of interest
is cloned into a suitable vector and grown in sufficient quantity
for analysis. Cells that express LGR7 or LGR8 may be used as a
source of mRNA, which may be assayed directly or reverse
transcribed into cDNA for analysis. The nucleic acid may be
amplified by conventional techniques, such as the polymerase chain
reaction (PCR), to provide sufficient amounts for analysis. The use
of the polymerase chain reaction is described in Saiki et al.
(1985) Science 239:487, and a review of techniques may be found in
Sambrook, et al. Molecular Cloning: A Laboratory Manual, CSH Press
1989, pp.14.2-14.33.
[0090] A detectable label may be included in an amplification
reaction. Suitable labels include fluorochromes, e.g. fluorescein
isothiocyanate (FITC), rhodamine, Texas Red, phycoerythrin,
allophycocyanin,6-carboxyflu-
orescein(6-FAM),2,7-dimethoxy-4,5-dichloro-6-carboxyfluorescein
(JOE), 6-carboxy-X-rhodamine (ROX),
6-carboxy-2,4,7,4,7-hexachlorofluorescein (HEX),
5-carboxyfluorescein (5-FAM) or N,N,N,N-tetramethyl-6-carboxyrhoda-
mine (TAMRA), radioactive labels, e.g. .sup.32P, .sup.35S, .sup.3H;
etc. The label may be a two stage system, where the amplified DNA
is conjugated to biotin, haptens, etc. having a high affinity
binding partner, e.g. avidin, specific antibodies, etc., where the
binding partner is conjugated to a detectable label. The label may
be conjugated to one or both of the primers. Alternatively, the
pool of nucleotides used in the amplification is labeled, so as to
incorporate the label into the amplification product.
[0091] The sample nucleic acid, e.g. amplified or cloned fragment,
is analyzed by one of a number of methods known in the art. The
nucleic acid may be sequenced by dideoxy or other methods, and the
sequence of bases compared to a wild-type LGR7 or LGR8 sequence.
Hybridization with the variant sequence may also be used to
determine its presence, by Southern blots, dot blots, etc. The
hybridization pattern of a control and variant sequence to an array
of oligonucleotide probes immobilized on an array, may also be used
as a means of detecting the presence of variant sequences. Single
strand conformational polymorphism (SSCP) analysis, denaturing
gradient gel electrophoresis(DGGE), and heteroduplex analysis in
gel matrices are used to detect conformational changes created by
DNA sequence variation as alterations in electrophoretic mobility.
Alternatively, where a polymorphism creates or destroys a
recognition site for a restriction endonucleases, the sample is
digested with that endonucleases, and the products size
fractionated to determine whether the fragment was digested.
Fractionation is performed by gel or capillary electrophoresis,
particularly acrylamide or agarose gels.
[0092] Screening for mutations in LGR7 or LGR8s may be based on the
functional or antigenic characteristics of the protein. Protein
truncation assays are useful in detecting deletions that may affect
the biological activity of the protein. Various immunoassays
designed to detect polymorphisms in LGR7 or LGR8 proteins may be
used in screening. Where many diverse genetic mutations lead to a
particular disease phenotype, functional protein assays have proven
to be effective screening tools. The activity of the encoded LGR7
or LGR8 protein in binding assays, etc., may be determined by
comparison with the wild-type protein. Proteins may also be
screened for the presence of post-translational modification of the
LGR7 or LGR8 proteins, e.g. under pathological conditions,
including proteolytic fragments, amidation, acetylation etc.
[0093] Antibodies specific for LGR7 or LGR8 may be used in staining
or in immunoassays. Samples, as used herein, include biological
fluids such as blood, amniotic fluid, and the like; organ or tissue
culture derived fluids; and fluids extracted from physiological
tissues. Also included in the term are derivatives and fractions of
such fluids. The cells may be dissociated, in the case of solid
tissues, or tissue sections may be analyzed. Alternatively a lysate
of the cells may be prepared.
[0094] Diagnosis may be performed by a number of methods to
determine the absence or presence or altered amounts of normal or
abnormal LGR7 or LGR8 in patient cells. For example, detection may
utilize staining of cells or histological sections, performed in
accordance with conventional methods. Cells are permeabilized to
stain cytoplasmic molecules. The antibodies of interest are added
to the cell sample, and incubated for a period of time sufficient
to allow binding to the epitope, usually at least about 10 minutes.
The antibody may be labeled with radioisotopes, enzymes,
fluorescers, chemiluminescers, or other labels for direct
detection. Alternatively, a second stage antibody or reagent is
used to amplify the signal. Such reagents are well known in the
art. For example, the primary antibody may be conjugated to biotin,
with horseradish peroxidase-conjugated avidin added as a second
stage reagent. Alternatively, the secondary antibody conjugated to
a fluorescent compound, e.g. fluorescein rhodamine, Texas red, etc.
Final detection uses a substrate that undergoes a color change in
the presence of the peroxidase. The absence or presence of antibody
binding may be determined by various methods, including flow
cytometry of dissociated cells, microscopy, radiography,
scintillation counting, etc.
[0095] In some embodiments, the methods are adapted for use in
vivo. In these embodiments, a detectably-labeled moiety, e.g., an
antibody, which is specific for LGR7 or LGR8 is administered to an
individual (e.g., by injection), and labeled cells are located
using standard imaging techniques, including, but not limited to,
magnetic resonance imaging, computed tomography scanning, and the
like.
[0096] Diagnostic screening may also be performed for polymorphisms
that are genetically linked to a disease predisposition,
particularly through the use of microsatellite markers or single
nucleotide polymorphisms. Frequently the microsatellite
polymorphism itself is not phenotypically expressed, but is linked
to sequences that result in a disease predisposition. However, in
some cases the microsatellite sequence itself may affect gene
expression. Microsatellite linkage analysis may be performed alone,
or in combination with direct detection of polymorphisms, as
described above. The use of microsatellite markers for genotyping
is well documented. For examples, see Mansfield et al. (1994)
Genomics 24:225-233; Ziegle et al. (1992) Genomics 14:1026-1031;
Dib et al., supra.
[0097] The detection methods can be provided as part of a kit.
Thus, the invention further provides kits for detecting the
presence of an mRNA encoding LGR7 or LGR8, and/or a polypeptide
encoded thereby, in a biological sample. Procedures using these
kits can be performed by clinical laboratories, experimental
laboratories, medical practitioners, or private individuals. The
kits of the invention for detecting a polypeptide comprise a moiety
that specifically binds the polypeptide, which may be a specific
antibody. The kits of the invention for detecting a nucleic acid
comprise a moiety that specifically hybridizes to such a nucleic
acid. The kit may optionally provide additional components that are
useful in the procedure, including, but not limited to, buffers,
developing reagents, labels, reacting surfaces, means for
detection, control samples, standards, instructions, and
interpretive information.
Genetically Altered Cell or Animal Models for LGR7 or LGR8
Function
[0098] The subject nucleic acids can be used to generate transgenic
animals or site specific gene modifications in cell lines.
Transgenic animals may be made through homologous recombination,
where the normal LGR7 or LGR8 locus is altered. Alternatively, a
nucleic acid construct is randomly integrated into the genome.
Vectors for stable integration include plasmids, retroviruses and
other animal viruses, YACs, and the like.
[0099] The modified cells or animals are useful in the study of
LGR7 or LGR8 function and regulation. For example, a series of
small deletions and/or substitutions may be made in the LGR7 or
LGR8 gene to determine the role of different residues in ligand
binding, signal transduction, etc. Of interest are the use of LGR7
or LGR8 to construct transgenic animal models for pregnancy related
disorders, connective tissue disorders, etc. where expression of
LGR7 or LGR8 is specifically reduced or absent. Specific constructs
of interest include anti-sense LGR7 or LGR8, which will block LGR7
or LGR8 expression and expression of dominant negative LGR7 or LGR8
mutations. A detectable marker, such as lac Z may be introduced
into the LGR7 or LGR8 locus, where up-regulation of LGR7 or LGR8
expression will result in an easily detected change in
phenotype.
[0100] One may also provide for expression of the LGR7 or LGR8 gene
or variants thereof in cells or tissues where it is not normally
expressed or at abnormal times of development. By providing
expression of LGR7 or LGR8 protein in cells in which it is not
normally produced, one can induce changes in cell behavior, e.g. in
the control of endometriosis, alterations in connective tissue, and
the like.
[0101] DNA constructs for homologous recombination will comprise at
least a portion of the LGR7 or LGR8 gene with the desired genetic
modification, and will include regions of homology to the target
locus. The regions of homology may include coding regions, or may
utilize intron and/or genomic sequence. DNA constructs for random
integration need not include regions of homology to mediate
recombination. Conveniently, markers for positive and negative
selection are included. Methods for generating cells having
targeted gene modifications through homologous recombination are
known in the art. For various techniques for transfecting mammalian
cells, see Keown et al. (1990) Methods in Enzymology
185:527-537.
[0102] For embryonic stem (ES) cells, an ES cell line may be
employed, or embryonic cells may be obtained freshly from a host,
e.g. mouse, rat, guinea pig, etc. Such cells are grown on an
appropriate fibroblast-feeder layer or grown in the presence of
leukemia inhibiting factor (LIF). When ES or embryonic cells have
been transformed, they may be used to produce transgenic animals.
After transformation, the cells are plated onto a feeder layer in
an appropriate medium. Cells containing the construct may be
detected by employing a selective medium. After sufficient time for
colonies to grow, they are picked and analyzed for the occurrence
of homologous recombination or integration of the construct. Those
colonies that are positive may then be used for embryo manipulation
and blastocyst injection. Blastocysts are obtained from 4 to 6 week
old superovulated females. The ES cells are trypsinized, and the
modified cells are injected into the blastocoel of the blastocyst.
After injection, the blastocysts are returned to each uterine horn
of pseudopregnant females. Females are then allowed to go to term
and the resulting offspring screened for the construct. By
providing for a different phenotype of the blastocyst and the
genetically modified cells, chimeric progeny can be readily
detected.
[0103] The chimeric animals are screened for the presence of the
modified gene and males and females having the modification are
mated to produce homozygous progeny. If the gene alterations cause
lethality at some point in development, tissues or organs can be
maintained as allogeneic or congenic grafts or transplants, or in
culture. The transgenic animals may be any non-human mammal, such
as laboratory animals, domestic animals, etc. The transgenic
animals may be used in functional studies, drug screening, etc.,
e.g. to determine the effect of a candidate drug on pregnancy and
birth, etc.
Experimental
[0104] The following examples are put forth so as to provide those
of ordinary skill in the art with a complete disclosure and
description of how to make and use the subject invention, and are
not intended to limit the scope of what is regarded as the
invention. Efforts have been made to ensure accuracy with respect
to the numbers used (e.g. amounts, temperature, concentrations,
etc.) but some experimental errors and deviations should be allowed
for. Unless otherwise indicated, parts are parts by weight,
molecular weight is average molecular weight, temperature is in
degrees centigrade; and pressure is at or near atmospheric.
EXAMPLE 1
[0105] Four orphan receptors, LGR4-7, have recently been isolated.
These have structural features similar to those of the gonadotropin
and thyrotropin receptors. Based on structural motifs and
phylogenetic analysis, the orphan LGRs could be subdivided into two
subgroups, with LGR4-6 as one group and LGR7 as another.
Orthologous genes for each subgroup of LGR have been found in
invertebrates. Similar to its snail and fly orthologs, human LGR7
has a unique N-terminal cysteine-rich LDL receptor-like domain
preceding the multiple leucine-rich repeats found in the ectodomain
of all other LGRs. Furthermore, constitutively active LGR7 mutants
showing ligand-independent cAMP production were constructed based
on gain-of-function point mutations found in the LH receptor of
patients with male-limited precocious puberty.
[0106] A new human LGR is identified herein, which belongs to the
same subgroup as LGR7 and is named LGR8 based on the chronological
order of discovery. As shown in FIG. 1A, sequence analysis
indicated LGR8 shared about 60% identity with LGR7 in both the
ectodomain and the transmembrane region. Phylogenetic analysis
showed that LGR8 has the closest relatedness with LGR7 and a
Drosophila orthologous receptor as compared to other human LGRs
(FIG. 1B). Similar to the gain-of-function mutants identified for
LGR7, a LGR8 mutant with a D578G substitution in the transmembrane
VI of this receptor conferred ligand-independent increases in basal
cAMP production in transfected cells (FIG. 1C). These findings
suggested that LGR8, like LGR7, could couple with the Gs protein to
activate adenylate cyclase.
[0107] Although both LGR7 and LGR8 are orphan receptors, the
similar cryptorchidism phenotypes of InsL3 null mice and mutant
mice with a disruption of the mouse GREAT gene (an LGR8 ortholog)
led to the hypothesis that the relaxin family of peptide proteins
are the ligands for LGR7 and LGR8. This hypothesis was reinforced
by earlier reports showing relaxin stimulation of cAMP production
in endometrial, anterior pituitary and other cells.
[0108] 293T cells expressing human LGR7 or LGR8 were treated with
porcine relaxin. As shown in FIGS. 2A and B, relaxin treatment
resulted in dose-dependent increases in cAMP production with an
EC.sub.50 of 0.1 and 0.5 nM for LGR7 and LGR8, respectively. In
contrast, treatment with structural homologs, insulin, IGF-I, and
IGF-II, as well as an unrelated peptide hormone glucagon was
ineffective. The present findings demonstrate that relaxin is the
cognate ligand for two G protein-coupled receptors, LGR7 and LGR8,
capable of activating adenylate cyclases.
[0109] To determine whether the expression of LGR7 and LGR8 is
consistent with previous studies on relaxin target sites, the
expression pattern of LGR7 and LGR8 was determined in diverse human
tissues (FIG. 3A). Reverse transcription-PCR analysis using a panel
of 23 different human cDNAs indicated that LGR7 is expressed in
diverse tissues as demonstrated previously using Northern blotting
analysis, whereas LGR8 is mainly present in the brain, kidney,
muscle, testis, thyroid, uterus, bone marrow and peripheral blood
cells. Specific antibodies were generated against the ectodomain of
LGR7. Immunohistochemical analysis demonstrated that the expression
of LGR7 is cell type-specific in different rodent tissues. In the
uterus, the expression of LGR7 is mainly in the endometrial and
muscularis layers but minimal in stromal and interstitial cells,
consistent with the utero-muscular modulating activity of relaxin.
In the cervix, LGR7 was found in all muscularis layer. In contrast,
negligible staining was found in the skeletal muscle (FIG. 3B).
[0110] Studies on the classical LGRs have demonstrated that the
ectodomains of gonadotropin and thyrotropin receptors are the
ligand-binding regions and an anchored receptor approach was
previously used to derive the soluble ectodomains of these
receptors as functional antagonists. Using this strategy, permanent
cell lines expressing the ectodomain of LGR7 fused to the single
transmembrane region of CD8 through a thrombin cleavage site were
isolated (FIG. 4A). Following thrombin treatment, mg quantities of
the soluble ectodomain of LGR7, named as 7BP, was generated. As
shown in FIG. 4B, cross-linking analysis demonstrated a
concentration-dependent formation of complexes between relaxin and
7BP whereas a homologous soluble ectodomain from rat LGR4 (4BP)
showed negligible interaction with relaxin. In addition,
co-treatment with 7BP dose-dependently blocked the stimulatory
effects of relaxin to activate LGR7 and LGR8 expressed in 293T
cells (FIG. 4C), but co-treatment with 4BP was ineffective.
Consistent with an earlier finding, treatment with relaxin
stimulated cAMP production by cultured rat myometrial cells (FIG.
4D). This stimulatory effect of relaxin was also antagonized by
co-treatment with 7BP.
[0111] Furthermore, subcutaneous administration of 7BP (500
.mu.g/day) for 4 days between post-conception days 17 and 20 in
pregnant mice led to parturition delay and nipple malformation
(Table 1).
1TABLE 1 Delay of Parturition and Inhibition of Nipple Development
by 7BP Control 7BP treatment Pregnancy Duration 508.8 .+-. 8.9
532.2 .+-. 9.0 (hours) Nipple size 1.55 .+-. 0.1 1.01 .+-. 0.06
(length .times. width, mm.sup.2)
[0112] Prolonged duration of straining was found. There were lower
incidences of normal maternal behavior observed at birth. In
addition, little or no milk was observed in the abdomen of most
live pups of 7BP-treated mice, whereas abundant milk was observed
in the abdomen of all live pups of control mice. The inability of
7BP-treated mother to nurse the young is consistent with findings
in relaxin null mice. Although earlier studies have used
neutralizing antibodies to relaxin to delay parturition in pregnant
rats, a more pronounced antagonistic effect of 7BP was observed
here, suggesting that other endogenous ligands for LGR7, in
addition to relaxin, could be important in the parturition
process.
[0113] The present identification of two orphan G protein-coupled
receptors as relaxin receptors is in direct contrast to the
well-known signaling mechanism of insulin and IGFs mediated by the
tetrameric tyrosine kinase receptors. Although relaxin has been
traditionally classified in the insulin family of hormones based on
similar domain arrangements, the present results indicated that
relaxin and related ligands could have diverged from insulin/IGF
ligands before separation of the arthropods because an ortholog of
LGR7 and LGR8 could be found in the fly genome (FIG. 1C) in
addition to receptors homologous to the other two subgroups of
mammalian LGRs (9).
[0114] The insulin ligand-signaling receptor system has been found
to be important in nutrition, longevity, and reproduction in the C.
elegans. It is likely that a subgroup of relaxin-related ligands
evolved early to subserve tissue remodeling functions including
actions on reproductive tracts in modern mammals. Indeed, a
relaxin-like gene has been found in the primitive tunicates whereas
a putative insulin-like protein in Drosophila exhibited greater
sequence homology to mammalian relaxin than to insulin and IGFs.
The proposed evolution of divergent receptor mechanisms for relaxin
and insulin are consistent with their crystal structure analyses.
Although relaxin, like insulin, crystallizes as a dimer, the
orientation of the molecules in the respective dimers is completely
different. Because the dimer interface determinants proposed for
receptor binding for insulin and relaxin are quite different, it
was proposed that these two structurally related hormones have
evolved somewhat dissimilar mechanisms for receptor binding.
[0115] The identification of cAMP as a second messenger for relaxin
is consistent with earlier findings of relaxin stimulation of cAMP
production by human endometrial and rat pituitary cells as well as
mouse pubic symphysis and rat cervical fragments. Unlike insulin,
relaxin gene sequences are highly variable among different
vertebrate species studied. The present availability of recombinant
human LGR7 and LGR8 can provide uniform and convenient in vitro
bioassays for relaxin, whereas the derivation of the soluble
ligand-binding ectodomains can serve as functional antagonists for
relaxin during tissue remodeling processes and pregnancy in human
and lower species.
[0116] Although relaxin activates both LGR7 and LGR8 based on
studies of recombinant receptors (FIG. 2), LGR7 is likely to
mediate both endocrine and paracrine actions of relaxin whereas
LGR8 is more important for a paracrine role, based on the observed
lower sensitivity of LGR8 to relaxin. The existence of two relaxin
receptors with overlapping tissue expression patterns raises issues
regarding their respective physiological roles. LGR7 is expressed
in tissues known to possess relaxin binding sites, including ovary,
testis, uterus, brain, and heart. Because LGR7 transcript was also
found in many tissues not previously known to be relaxin targets,
it is interesting to analyze the potential action of relaxin in
these tissues. In contrast, the expression of LGR8 is more
restricted.
[0117] Although antepartum increases in circulating relaxin has
been found in rat and selected species, relaxin may be a paracrine
hormone in humans and is secreted by corpus luteum, placenta, and
uterus to subserve local functions. The differential expression of
LGR7 and LGR8 and the possible involvement of additional ligands
for these receptors provide the basis to elucidate the role of
these receptors and their ligands during pregnant states.
Identification of LGR7 and LGR8 as relaxin receptors provides the
basis to elucidate the differential ligand specificity and tissue
distribution of these two proteins for the understanding of the
diverse actions of relaxin during pregnant and nonpregnant
states.
[0118] Preterm labor and delivery remain a major cause of perinatal
morbidity, mortality, and long-term adverse neurodevelopmental
outcome, whereas prolonged labor is also associated with major
stress for mothers and infants. Although conflicting outcome has
been reported for the use of relaxin as a labor-inducing agent,
future studies on the signal transduction mechanism of relaxin
receptors will allow the design of agonistic or antagonistic
relaxin analogs for the treatment of disorders of labor onset.
Elucidation of the ligand signaling mechanisms of relaxin receptors
will also lead to a better understanding of the role of relaxin and
related hormones in uterine and mammary growth. In addition to
actions on reproductive tissues, relaxin has been shown to regulate
pituitary prolactin, oxytocin, and vasopressin release, probably by
binding to putative receptors in brain and pituitary. In addition,
relaxin binding sites have been found in mast cells, and a human
monocytic cell line.
[0119] Relaxin has important effects on the vascular system. It is
angiogenic in the endometrial lining and plays a role in the
attachment of the embryo to the uterus, and structural remodeling
of the abdomen, joints and tendons to accommodate the growing
fetus. In addition, relaxin regulates the circulatory system to
ensure adequate blood flow and oxygenation to the growing fetus. It
stimulates vasodilation of vascular beds by activating the
endothelin B receptor subtype and inhibiting the vasoconstrictive
effects of angiotensin II. Relaxin also acts as an
anti-fibrinolytic agent by decreasing collagen production,
increasing collagen breakdown, and reducing the production of the
collagenase inhibitor, TIMP. Understanding of the vascular
activities of relaxin mediated by its receptors will allow
stimulation of new blood vessel growth in selective target tissues
and ischemic wound sites.
[0120] Studies on this relaxin receptor will facilitate
understandings on connective tissue remodeling and allow new
treatments of skin conditions such as scleroderma. Although the
major biological effect of relaxin is to remodel the mammalian
reproductive tract and breast in pregnant females to facilitate the
birth process and nursing, high levels of relaxin secreted by the
prostate has also been found in human seminal plasma and might play
a role in sperm motility and fertilization capacity. The present
elucidation of relaxin receptors could facilitate the understanding
of the role of relaxin in males.
[0121] The present study underscored the value of a genomic
approach in the matching of orphan ligand-receptor pairs. Although
relaxin has domain arrangements similar to those of the insulin/lGF
family of proteins known to activate tetrameric tyrosine kinase
receptors, the completely sequenced human genome has only one
orphan insulin receptor-like gene that is unlikely to be the
receptor for the divergent relaxin-like factors. Likewise, the
analysis of paralogs of glycoprotein hormone subunit genes
indicated that the limited number of remaining candidate ligands is
unlikely to interact with orphan LGRs. Thus, the orphan LGRs are
likely to interact with ligands other than the heterodimeric
gonadotropins and thyrotropin.
[0122] The present demonstration of LGR7 and LGR8 as relaxin
receptors indicated that a separate ligand signaling system has
evolved for the relaxin subfamily of insulin-like genes, including
InsL3 and relaxin. Similar to the ancient origin of the insulin
ligand/receptor system, structural orthologs forLGR7 and LGR8 could
be traced to fly and snail, and phylogenetic analysis indicated
that this subgroup of LGRs evolved before the emergence of
Bilateria. Thus, the usage of two distinct receptor-signaling
mechanisms for structurally-related insulin and relaxin family of
peptide ligands is likely to be ancient in origin. It is becoming
clear that the actions of relaxin and its related ligands (e.g.
InsL3) are mediated by at least two related LGRs (7 and 8). Based
on the hypothesized coevolution of the relaxin family of ligands
and the orphan LGRs, future studies on the matching of InsL3 and
related relaxin-like ligands (InsL4, RIF1, and RIF2) with LGR8 and
the remaining orphan LGRs (LGR4-6) are of interest.
EXAMPLE 2
[0123] INSL3, also known as Leydig insulin-like peptide or
relaxin-like factor, is a relaxin family member expressed in testis
Leydig cells and ovarian theca and luteal cells. Male mice mutant
for INSL3 exhibit cryptorchidism or defects in testis descent due
to abnormal gubernaculum development whereas overexpression of
INSL3 induces ovary descent in transgenic females. Because
transgenic mice missing the LGR8 gene are also cryptorchid, INSL3
was tested as the ligand for LGR8. Here, it is shown that treatment
with INSL3 stimulated cAMP production in cells expressing
recombinant LGR8, but not LGR7. In addition, interactions between
INSL3 and LGR8 were demonstrated following ligand receptor
cross-linking. Northern blot analysis indicated that the LGR8
transcripts are expressed in gubernaculum whereas treatment of
cultured gubernacular cells with INSL3 stimulated cAMP production
and thymidine incorporation. Demonstration of INSL3 as the ligand
for LGR8 facilitates understanding of the mechanism of testis
descent and allows studies on the role of INSL3 in gonadal and
other physiological processes.
[0124] Experimental Procedures:
[0125] Ovine and rat INSL3 were chemically synthesized and
characterized as previously described. Human INSL3 and biotinylated
ovine INSL3 were prepared similarly with the ovine INSL3 containing
a single biotin molecule on the N-terminus of the A chain. The
National Hormone and Pituitary Program (NIDDK, National Institutes
of Health, Bethesda, Md.) supplied porcine relaxin.
.sup.125I-Streptavidin and streptavidin conjugated to horseradish
peroxidase (HRP) were purchased from Amersham Biosciences, Inc
(Piscataway, N.J.), whereas foskolin, glucagon, collagenase and
trypsin were from Sigma Chemical Co. (St. Louis, Mo.).
Sprague-Dawley rats were obtained from Simonsen Laboratories
(Gilroy, Calif.). Animals were anesthetized and killed using
CO.sub.2. Animal care was consistent with institutional and NIH
guidelines.
[0126] Human 293T cells were maintained in Dulbecco's modified
Eagle's medium/Ham's F-12 (DMEM/F12) supplemented with 10% fetal
bovine serum (FBS), 100 .mu.g/ml penicillin, 100 .mu.g/ml
streptomycin, and 2 mM L-glutamine. When 70-80% confluent, cells
were transfected with 10 .mu.g of plasmid using the calcium
phosphate precipitation method. After 18-24 h of incubation, media
were replaced with DMEM/F12 containing 10% FBS. Forty-eight hours
after transfection, cells (10.sup.5/ml) were preincubated at
37.degree. C. for 30 min in the presence of 0.25 mM
3-isobutyl-1-methyl xanthine (IBMX, Sigma Chemical Co.) before
treatment with or without hormones for 12 h. Total cAMP content was
measured in triplicate by a specific radioimmunoassay. All
experiments were repeated at least four times using cells from
independent transfections.
[0127] To estimate INSL3 binding, transfected cells were washed
twice with D-PBS and collected in D-PBS before centrifugation at
400.times.g for 5 min. Cells pellets were resuspended in D-PBS
containing 1 mg/ml BSA and incubated with increasing doses of the
rat INSL3 at 4.degree. C. for 24 h in the presence of biotinylated
INSL3 (5 nM/tube). After incubation, cells were centrifuged and
washed twice with 1% BSA/PBS before incubation with
.sup.125I-Streptavidin (400,000 cpm/tube) for 1 h at 4.degree. C.
After washing the cells three times, radioactivity in the pellets
was determined. For protein blotting, transfected cells were
incubated with biotinylated INSL3 (50 nM/tube) with or without an
excess of rat INSL3 (1 .mu.M/tube). After washing, pellets were
incubated in D-PBS with disuccinimidyl suberate (0.5 mM) for 30
min. at room temperature. The cross-linked INSL3-LGR8 complexes
were solubilized with 100 .mu.l 1% Triton X-100 in 50 mM Tris-HCl.
The lysates were denatured with SDS and 2-beta-mercaptoethanol, and
fractionated using SDS-PAGE. After blotting onto nitrocellulose
membranes (Hybond-P, Amersham) and blocking with a 5% milk
solution, the blots were incubated for 2 h at room temperature with
streptavidin (1:10,000 dilution) before development using enhanced
chemiluminescence solution (ECL, Amersham Life Science). In
addition, epitope-tagged LGR8 was extracted with 1% Triton X-100
from cells transfected with the LGR8 expression plasmid and
incubated with the M1 antibody for 1 h. Protein G-Sepharose was
subsequently added to precipitate the M1-tagged receptor protein.
The precipitate was further fractionated using SDS-PAGE followed by
immunoblotting using the M1 antibody.
[0128] Total RNA from different rat tissues were extracted using
the RNeasy purification kits (QIAGEN Inc. Chatsworth, Calif.)
before Northern blotting. Rat orthologs for LGR7 and LGR8 were
identified in the GenBank (accession number AC098607 and AC098990,
respectively). These sequences were used in reverse
transcription-PCR to yield LGR8 and LGR7 probes of 230 and 226 bp,
respectively.
[0129] Gubernacular cells were isolated by modifying an earlier
method. Tissues were removed from one-week-old rats and cut into 1
mm pieces, and dissociated for 2 h at 37.degree. C. in DMEM/F12
with 0.1% collagenase. Cell debris was removed by passage through a
sterile filter and cells were collected by centrifugation. After
suspension in DMEM/F12 with 10% FBS, 100 .mu.g/ml penicillin, 100
.mu.g/ml streptomycin, and 2 mM L-glutamine, cells were cultured
for 24 h in 5% CO.sub.2 incubator at 37.degree. C. The cells were
then washed once with serum-free medium and treated in DMEM/F12
containing IBMX with or without hormones and reagents. After 16 h
of incubation, total cAMP was measured in triplicates as described
above. For thymidine incorporation studies, gubernacular cells
(2.times.10.sup.5 cells/500 .mu.l) were cultured in 5 ml
polypropylene Falcon tubes (Becton Dickinson, Franklin Lakes, N.J.)
with or without hormones together with 1 .mu.Ci/tube of
[methyl-.sup.3H]thymidine (Amersham Pharmacia Biotech). After 24 h
of culture, cells were washed once and resuspended with ice-cold
PBS before centrifugation at 2000.times.g for 30 min. at 4.degree.
C. Radioactivities in the washed cell samples were determined using
a .beta.-photomultiplier.
[0130] Results
[0131] INSL3 is the cognate ligand for LGR8. Although INSL3 binds
to gubernacular homogenates, and induces growth of rat gubernaculum
in organ cultures, the exact nature of the INSL3 receptor is
unknown. Human fetal kidney 293T cells were transfected with
expression vectors encoding human LGR8 or the related LGR7 for
testing of INSL3 signaling. In cells expressing LGR8 (FIG. 5A),
treatment with synthetic human, ovine, or rat INSL3 led to
dose-dependent increases in cAMP production. Although treatment
with biotinylated-ovine INSL3 or porcine relaxin (RLX) was also
effective, treatment with glucagon did not increase cAMP
production. In contrast, cells expressing LGR7 responded only to
relaxin treatment whereas treatments with INSL3 from different
species or human glucagon were ineffective (FIG. 5B). These results
indicated that INSL3 is a specific ligand for LGR8.
[0132] To demonstrate the direct binding of INSL3 to LGR8, cells
expressing LGR8 were incubated with biotinylated INSL3 with or
without increasing doses of non-biotinylated INSL3. Following
incubation at 4 C. for 24 h, cells were washed and incubated
further with I.sup.125-labeled streptavidin to estimate the levels
of cell-bound biotinylated INSL3. As shown in FIG. 6A, specific
binding of biotinylated INSL3 to LGR8 could be competed by
non-biotinylated INSL3 in a dose-dependent manner with an ED.sub.50
of 12 nM (filled circles). In contrast, 293T cells without LGR8
expression did not exhibit specific binding (open triangles). The
formation of the LGR8-INSL3 complexes was further estimated
following cross-linking and protein blotting before signal
detection using avidin-horseradish peroxidase (HRP). As shown in
FIG. 6B, biotinylated INSL3 cross-linked with LGR8 could be
detected as a high MW band (.about.84 KDa) whereas a 20-fold excess
of non-biotinylated INSL3 decreased signal intensity (lanes 2 and
3). In contrast, the free biotinylated INSL3 migrated at 6.5 KDa
(FIG. 6B, lane 1) and the epitope-tagged LGR8 extracted from
transfected cells migrated at .about.75 KDa when monitored using
the M1 antibody after immunoprecipitation with the same antibody
(FIG. 6B, lane 4).
[0133] Expression of LGR8 in gubernaculum and INSL3 stimulation of
gubernacular functions. Northern blotting analyses demonstrated the
expression of the LGR8 transcript in the gubernaculum of
one-week-old immature rats and testis of adult rats, but not in
diaphragm (FIG. 7A). In the gubernaculum, a single transcript of
.about.2.5 kb was evident whereas an additional transcript of a
higher size was found in the testis. In addition, treatment of
gubernacular cells with INSL3 led to dose-dependent increases in
cAMP production (FIG. 7B) to levels comparable to cells treated
with forskolin (FS), a diterpene adenyl cyclase activator. Although
glucagon treatment was ineffective, treatment with relaxin also
stimulated cAMP production by these cells, consistent with its
ability to activate LGR8. For diaphragm cells, none of the hormones
tested elicited cAMP production despite the stimulatory effects of
forskolin (FIG. 7B). Because an increase in gubernacular cell
division is believed to be needed during testis descent, the
ability of INSL3 to stimulate thymidine incorporation by cultured
gubernacular cells was tested. As shown in FIG. 7C, treatment with
INSL3 led to dose-dependent increases in thymidine incorporation by
these cells. In addition, treatment with relaxin and forskolin, but
not glucagon, was also effective.
[0134] The present findings demonstrate that INSL3 is the cognate
ligand for LGR8. The observed expression of LGR8 transcripts in the
gubernaculum and the INSL3 stimulation of cAMP production by these
cells are consistent with the common cryptorchid phenotypes of this
ligand-receptor pair in earlier transgenic mouse studies. Although
the large 550 kb DNA deletion induced in transgenic mice following
random insertional mutagenesis includes genes other than the mouse
LGR8 ortholog, present findings of the ligand-receptor relationship
for INLS3 and LGR8 supports the hypothesis that deletion of this
receptor gene alone is responsible for the cryptorchid phenotype.
Despite the bilateral cryptorchidism found in male INSL3 null mice
as a result of developmental abnormalities of the gubernaculum,
most studies indicated that INSL3 gene mutations are not associated
with cryptorchidism in patients. Two putative mutations, R49X and
P69L, were identified in the connecting peptide region of the
precursor INSL3 protein. Because the frequency of these INSL3 gene
mutations is low (1.4%), their potential influence on testis
descent waits further testing. The present identification of LGR8
as the receptor for INSL3 raised the possibility that partial or
complete loss-of-function mutations in the LGR8 gene are associated
with cryptorchidism, the most frequent congenital abnormalities in
humans.
[0135] INSL3 specifically activates LGR8, but not LGR7. A total of
seven relaxin members are present in the human genome. Relaxin H1
and H2 are clustered together with INSL4 and INSL6 in chromosome
9p23-24 whereas INSL3 is located together with relaxin 3 in 19p13.
The present findings provide the basis to test the receptor binding
specificity of other relaxin paralogs, thus allowing a better
understanding of the evolution and physiology of the relaxin ligand
gene family. Based on the divergent receptor specificity of relaxin
and INSL3, future chimeric receptor studies on the ligand
specificity of LGR7 and LGR8 are also of interest.
[0136] During fetal development, the sexual dimorphic position in
mammalian gonads is dependent on the differential development of
two ligaments. In males, growth of the gubernaculum and regression
of the cranial suspensory ligament result in transabdominal descent
of the testes. Circulating INSL3 concentrations increase in male
rats starting at day 10 of age and continuing until INSL3
concentrations reached adult levels at day 39 after parturition.
The testicles are descending into the scrotum during this phase of
increasing INSL3 concentrations. INSL3 is expressed in Leydig cells
of the fetal and postnatal testis and also in theca and luteal
cells of the postnatal ovary, whereas LGR8 is expressed in multiple
tissues including testis, brain, kidney, muscle, thyroid, uterus,
peripheral blood cells, and bone marrow. In addition to its
endocrine role in testis descent mediated by LGR8 in gubernaculum,
INSL3 could also have important endocrine or paracrine roles in
other tissues. Although defective spermatogenesis found in INSL3 or
LGR8 null mice could be the secondary effects of cryptorchidism,
Leydig cell-derived INSL3 could play a paracrine role in the testis
because LGR8 is also expressed in the testis. In females, INSL3 is
expressed in the luteal cells of the ovary through the cycle, and
during pregnancy. Because female INSL3 null mice have impaired
fertility associated with deregulation of the estrous cycle, the
present findings will facilitate understanding of the paracrine
role of INSL3 in the ovary in addition to providing understandings
on the physiological roles of LGR8 in non-gonadal tissues such as
brain, thyroid, and uterus.
[0137] All publications and patent applications cited in this
specification are herein incorporated by reference as if each
individual publication or patent application were specifically and
individually indicated to be incorporated by reference. The
publications discussed herein are provided solely for their
disclosure prior to the filing date of the present application.
Nothing herein is to be construed as an admission that the
invention is not entitled to antedate such a disclosure by virtue
of prior invention.
[0138] Although the foregoing invention has been described in some
detail by way of illustration and example for purposes of clarity
of understanding, it will be readily apparent to those of ordinary
skill in the art in light of the teachings of this invention that
certain changes and modifications may be made thereto without
departing from the spirit or scope of the appended claims.
Sequence CWU 1
1
4 1 2838 DNA H. sapiens CDS (107)...(2369) 1 actcactata gggctcgagc
ggccgcccgg gcaggtgaac ttactacatc agaactcctg 60 ctgaggtata
agaggatacg tctaataact caattgctgt aaacct atg att gtt 115 Met Ile Val
1 ttt ctg gtt ttt aaa cat ctc ttc agc ctc aga ttg att aca atg ttc
163 Phe Leu Val Phe Lys His Leu Phe Ser Leu Arg Leu Ile Thr Met Phe
5 10 15 ttt cta ctt cat ttc atc gtt ctg atc aat gtc aaa gat ttt gca
ctg 211 Phe Leu Leu His Phe Ile Val Leu Ile Asn Val Lys Asp Phe Ala
Leu 20 25 30 35 act caa ggt agc atg atc act cct tca tgc caa aaa gga
tat ttt ccc 259 Thr Gln Gly Ser Met Ile Thr Pro Ser Cys Gln Lys Gly
Tyr Phe Pro 40 45 50 tgt ggg aat ctt acc aag tgc tta ccc cga gct
ttt cac tgt gat ggc 307 Cys Gly Asn Leu Thr Lys Cys Leu Pro Arg Ala
Phe His Cys Asp Gly 55 60 65 aag gat gac tgt ggg aac ggg gcg gac
gaa gag aac tgt ggt gac act 355 Lys Asp Asp Cys Gly Asn Gly Ala Asp
Glu Glu Asn Cys Gly Asp Thr 70 75 80 agt gga tgg gcg acc ata ttt
ggc aca gtg cat gga aat gct aac agc 403 Ser Gly Trp Ala Thr Ile Phe
Gly Thr Val His Gly Asn Ala Asn Ser 85 90 95 gtg gcc tta aca cag
gag tgc ttt cta aaa cag tat cca caa tgc tgt 451 Val Ala Leu Thr Gln
Glu Cys Phe Leu Lys Gln Tyr Pro Gln Cys Cys 100 105 110 115 gac tgc
aaa gaa act gaa ttg gaa tgt gta aat ggt gac tta aag tct 499 Asp Cys
Lys Glu Thr Glu Leu Glu Cys Val Asn Gly Asp Leu Lys Ser 120 125 130
gtg ccg atg att tct aac aat gtg aca tta ctg tct ctt aag aaa aac 547
Val Pro Met Ile Ser Asn Asn Val Thr Leu Leu Ser Leu Lys Lys Asn 135
140 145 aaa atc cac agt ctt cca gat aaa gtt ttc atc aaa tac aca aaa
ctt 595 Lys Ile His Ser Leu Pro Asp Lys Val Phe Ile Lys Tyr Thr Lys
Leu 150 155 160 aaa aag ata ttt ctt cag cat aat tgc att aga cac ata
tcc agg aaa 643 Lys Lys Ile Phe Leu Gln His Asn Cys Ile Arg His Ile
Ser Arg Lys 165 170 175 gca ttt ttt gga tta tgt aat ctg caa ata tta
tat ctc aac cac aac 691 Ala Phe Phe Gly Leu Cys Asn Leu Gln Ile Leu
Tyr Leu Asn His Asn 180 185 190 195 tgc atc aca acc ctc aga cct gga
ata ttc aaa gac tta cat cag cta 739 Cys Ile Thr Thr Leu Arg Pro Gly
Ile Phe Lys Asp Leu His Gln Leu 200 205 210 act tgg cta att cta gat
gac aat cca ata acc aga att tca cag cgc 787 Thr Trp Leu Ile Leu Asp
Asp Asn Pro Ile Thr Arg Ile Ser Gln Arg 215 220 225 ttg ttt acg gga
tta aat tcc ttg ttt ttc ctg tct atg gtt aat aac 835 Leu Phe Thr Gly
Leu Asn Ser Leu Phe Phe Leu Ser Met Val Asn Asn 230 235 240 tac tta
gaa gct ctt ccc aag cag atg tgt gcc caa atg cct caa ctc 883 Tyr Leu
Glu Ala Leu Pro Lys Gln Met Cys Ala Gln Met Pro Gln Leu 245 250 255
aac tgg gtg gat ttg gaa ggc aat aga ata aag tat ctc aca aat tct 931
Asn Trp Val Asp Leu Glu Gly Asn Arg Ile Lys Tyr Leu Thr Asn Ser 260
265 270 275 acg ttt ctg tcg tgc gat tcg ctc aca gtg ctg ttt ctg cct
aga aat 979 Thr Phe Leu Ser Cys Asp Ser Leu Thr Val Leu Phe Leu Pro
Arg Asn 280 285 290 caa att ggt ttt gtt cca gag aag aca ttt tct tca
tta aaa aat tta 1027 Gln Ile Gly Phe Val Pro Glu Lys Thr Phe Ser
Ser Leu Lys Asn Leu 295 300 305 gga gaa ctg gat ctg tct agc aat acg
ata acg gag cta tca cct cac 1075 Gly Glu Leu Asp Leu Ser Ser Asn
Thr Ile Thr Glu Leu Ser Pro His 310 315 320 ctt ttt aaa gac ttg aag
ctt cta caa aag ctg aac ctg tca tcc aat 1123 Leu Phe Lys Asp Leu
Lys Leu Leu Gln Lys Leu Asn Leu Ser Ser Asn 325 330 335 cct ctt atg
tat ctt cac aag aac cag ttt gaa agt ctt aaa caa ctt 1171 Pro Leu
Met Tyr Leu His Lys Asn Gln Phe Glu Ser Leu Lys Gln Leu 340 345 350
355 cag tct cta gac ctg gaa agg ata gag att cca aat ata aac aca cga
1219 Gln Ser Leu Asp Leu Glu Arg Ile Glu Ile Pro Asn Ile Asn Thr
Arg 360 365 370 atg ttt caa ccc atg aag aat ctt tct cac att tat ttc
aaa aac ttt 1267 Met Phe Gln Pro Met Lys Asn Leu Ser His Ile Tyr
Phe Lys Asn Phe 375 380 385 cga tac tgc tcc tat gct ccc cat gtc cga
ata tgt atg ccc ttg acg 1315 Arg Tyr Cys Ser Tyr Ala Pro His Val
Arg Ile Cys Met Pro Leu Thr 390 395 400 gac ggc att tct tca ttt gag
gac ctc ttg gct aac aat atc ctc aga 1363 Asp Gly Ile Ser Ser Phe
Glu Asp Leu Leu Ala Asn Asn Ile Leu Arg 405 410 415 ata ttt gtc tgg
gtt ata gct ttc att acc tgc ttt gga aat ctt ttt 1411 Ile Phe Val
Trp Val Ile Ala Phe Ile Thr Cys Phe Gly Asn Leu Phe 420 425 430 435
gtc att ggc atg aga tct ttc att aaa gct gaa aat aca act cac gct
1459 Val Ile Gly Met Arg Ser Phe Ile Lys Ala Glu Asn Thr Thr His
Ala 440 445 450 atg tcc atc aaa atc ctt tgt tgt gct gat tgc ctg atg
ggt gtt tac 1507 Met Ser Ile Lys Ile Leu Cys Cys Ala Asp Cys Leu
Met Gly Val Tyr 455 460 465 ttg ttc ttt gtt ggc att ttc gat ata aaa
tac cga ggg cag tat cag 1555 Leu Phe Phe Val Gly Ile Phe Asp Ile
Lys Tyr Arg Gly Gln Tyr Gln 470 475 480 aag tat gcc ttg ctg tgg atg
gag agc gtg cag tgc cgc ctc atg ggg 1603 Lys Tyr Ala Leu Leu Trp
Met Glu Ser Val Gln Cys Arg Leu Met Gly 485 490 495 ttc ctg gcc atg
ctg tcc acc gaa gtc tct gtt ctg cta ctg acc tac 1651 Phe Leu Ala
Met Leu Ser Thr Glu Val Ser Val Leu Leu Leu Thr Tyr 500 505 510 515
ttg act ttg gag aag ttc ctg gtc att gtc ttc ccc ttc agt aac att
1699 Leu Thr Leu Glu Lys Phe Leu Val Ile Val Phe Pro Phe Ser Asn
Ile 520 525 530 cga cct gga aaa cgg cag acc tca gtc atc ctc att tgc
atc tgg atg 1747 Arg Pro Gly Lys Arg Gln Thr Ser Val Ile Leu Ile
Cys Ile Trp Met 535 540 545 gcg gga ttt tta ata gct gta att cca ttt
tgg aat aag gat tat ttt 1795 Ala Gly Phe Leu Ile Ala Val Ile Pro
Phe Trp Asn Lys Asp Tyr Phe 550 555 560 gga aac ttt tat ggg aaa aat
gga gta tgt ttc cca ctt tat tat gac 1843 Gly Asn Phe Tyr Gly Lys
Asn Gly Val Cys Phe Pro Leu Tyr Tyr Asp 565 570 575 caa aca gaa gat
att gga agc aaa ggg tat tct ctt gga att ttc cta 1891 Gln Thr Glu
Asp Ile Gly Ser Lys Gly Tyr Ser Leu Gly Ile Phe Leu 580 585 590 595
ggt gtg aac ttg ctg gct ttt ctc atc att gtg ttt tcc tat att act
1939 Gly Val Asn Leu Leu Ala Phe Leu Ile Ile Val Phe Ser Tyr Ile
Thr 600 605 610 atg ttc tgt tcc att caa aaa acc gcc ttg cag acc aca
gaa gta agg 1987 Met Phe Cys Ser Ile Gln Lys Thr Ala Leu Gln Thr
Thr Glu Val Arg 615 620 625 aat tgt ttt gga aga gag gtg gct gtt gca
aat cgt ttc ttt ttt ata 2035 Asn Cys Phe Gly Arg Glu Val Ala Val
Ala Asn Arg Phe Phe Phe Ile 630 635 640 gtg ttc tct gat gcc atc tgc
tgg att cct gta ttt gta gtt aaa atc 2083 Val Phe Ser Asp Ala Ile
Cys Trp Ile Pro Val Phe Val Val Lys Ile 645 650 655 ctt tcc ctc ttc
cgg gtg gaa ata cca gac aca atg act tcc tgg ata 2131 Leu Ser Leu
Phe Arg Val Glu Ile Pro Asp Thr Met Thr Ser Trp Ile 660 665 670 675
gtg att ttt ttc ctt cca gtt aac agt gct ttg aat cca atc ctc tat
2179 Val Ile Phe Phe Leu Pro Val Asn Ser Ala Leu Asn Pro Ile Leu
Tyr 680 685 690 act ctc aca acc aac ttt ttt aag gac aag ttg aaa cag
ctg ctg cac 2227 Thr Leu Thr Thr Asn Phe Phe Lys Asp Lys Leu Lys
Gln Leu Leu His 695 700 705 aaa cat cag agg aaa tca att ttc aaa att
aaa aaa aaa agt tta tct 2275 Lys His Gln Arg Lys Ser Ile Phe Lys
Ile Lys Lys Lys Ser Leu Ser 710 715 720 aca tcc att gtg tgg ata gag
gac tcc tct tcc ctg aaa ctt ggg gtt 2323 Thr Ser Ile Val Trp Ile
Glu Asp Ser Ser Ser Leu Lys Leu Gly Val 725 730 735 ttg aac aaa ata
aca ctt gga gac agt ata atg aaa cca gtt tcc t 2369 Leu Asn Lys Ile
Thr Leu Gly Asp Ser Ile Met Lys Pro Val Ser 740 745 750 agcaatcatt
ttggatcact ggactttcag tggactacct aaaacagggg acagcttttg 2429
gaagatgaca tctgcaatgc ttttcatctt taccaacggc aagcctttct gcacagagag
2489 cacagcagaa tggctcctgt cactgcattc caatggcagc tgtactatct
accaaccatg 2549 ctgaggacag caccaaaggt tcctctcctc accccacatg
cctgaaaagc acatgtgaat 2609 tcgtgtatag tgggctgagg tgcagctgat
ctctagctaa tcaacacaac ccaccaacaa 2669 atgaccacag gttggcactg
tgtggtcttt cacatcgggt tgcactgtcc atgaaataga 2729 aacactcaca
acatctgatt ccagtgtggc cataataaca gaaatctaac aactctttcc 2789
ttgccttttc aatatcaaat aaaaccatca gcatcctgct ggattgata 2838 2 754
PRT H. sapiens 2 Met Ile Val Phe Leu Val Phe Lys His Leu Phe Ser
Leu Arg Leu Ile 1 5 10 15 Thr Met Phe Phe Leu Leu His Phe Ile Val
Leu Ile Asn Val Lys Asp 20 25 30 Phe Ala Leu Thr Gln Gly Ser Met
Ile Thr Pro Ser Cys Gln Lys Gly 35 40 45 Tyr Phe Pro Cys Gly Asn
Leu Thr Lys Cys Leu Pro Arg Ala Phe His 50 55 60 Cys Asp Gly Lys
Asp Asp Cys Gly Asn Gly Ala Asp Glu Glu Asn Cys 65 70 75 80 Gly Asp
Thr Ser Gly Trp Ala Thr Ile Phe Gly Thr Val His Gly Asn 85 90 95
Ala Asn Ser Val Ala Leu Thr Gln Glu Cys Phe Leu Lys Gln Tyr Pro 100
105 110 Gln Cys Cys Asp Cys Lys Glu Thr Glu Leu Glu Cys Val Asn Gly
Asp 115 120 125 Leu Lys Ser Val Pro Met Ile Ser Asn Asn Val Thr Leu
Leu Ser Leu 130 135 140 Lys Lys Asn Lys Ile His Ser Leu Pro Asp Lys
Val Phe Ile Lys Tyr 145 150 155 160 Thr Lys Leu Lys Lys Ile Phe Leu
Gln His Asn Cys Ile Arg His Ile 165 170 175 Ser Arg Lys Ala Phe Phe
Gly Leu Cys Asn Leu Gln Ile Leu Tyr Leu 180 185 190 Asn His Asn Cys
Ile Thr Thr Leu Arg Pro Gly Ile Phe Lys Asp Leu 195 200 205 His Gln
Leu Thr Trp Leu Ile Leu Asp Asp Asn Pro Ile Thr Arg Ile 210 215 220
Ser Gln Arg Leu Phe Thr Gly Leu Asn Ser Leu Phe Phe Leu Ser Met 225
230 235 240 Val Asn Asn Tyr Leu Glu Ala Leu Pro Lys Gln Met Cys Ala
Gln Met 245 250 255 Pro Gln Leu Asn Trp Val Asp Leu Glu Gly Asn Arg
Ile Lys Tyr Leu 260 265 270 Thr Asn Ser Thr Phe Leu Ser Cys Asp Ser
Leu Thr Val Leu Phe Leu 275 280 285 Pro Arg Asn Gln Ile Gly Phe Val
Pro Glu Lys Thr Phe Ser Ser Leu 290 295 300 Lys Asn Leu Gly Glu Leu
Asp Leu Ser Ser Asn Thr Ile Thr Glu Leu 305 310 315 320 Ser Pro His
Leu Phe Lys Asp Leu Lys Leu Leu Gln Lys Leu Asn Leu 325 330 335 Ser
Ser Asn Pro Leu Met Tyr Leu His Lys Asn Gln Phe Glu Ser Leu 340 345
350 Lys Gln Leu Gln Ser Leu Asp Leu Glu Arg Ile Glu Ile Pro Asn Ile
355 360 365 Asn Thr Arg Met Phe Gln Pro Met Lys Asn Leu Ser His Ile
Tyr Phe 370 375 380 Lys Asn Phe Arg Tyr Cys Ser Tyr Ala Pro His Val
Arg Ile Cys Met 385 390 395 400 Pro Leu Thr Asp Gly Ile Ser Ser Phe
Glu Asp Leu Leu Ala Asn Asn 405 410 415 Ile Leu Arg Ile Phe Val Trp
Val Ile Ala Phe Ile Thr Cys Phe Gly 420 425 430 Asn Leu Phe Val Ile
Gly Met Arg Ser Phe Ile Lys Ala Glu Asn Thr 435 440 445 Thr His Ala
Met Ser Ile Lys Ile Leu Cys Cys Ala Asp Cys Leu Met 450 455 460 Gly
Val Tyr Leu Phe Phe Val Gly Ile Phe Asp Ile Lys Tyr Arg Gly 465 470
475 480 Gln Tyr Gln Lys Tyr Ala Leu Leu Trp Met Glu Ser Val Gln Cys
Arg 485 490 495 Leu Met Gly Phe Leu Ala Met Leu Ser Thr Glu Val Ser
Val Leu Leu 500 505 510 Leu Thr Tyr Leu Thr Leu Glu Lys Phe Leu Val
Ile Val Phe Pro Phe 515 520 525 Ser Asn Ile Arg Pro Gly Lys Arg Gln
Thr Ser Val Ile Leu Ile Cys 530 535 540 Ile Trp Met Ala Gly Phe Leu
Ile Ala Val Ile Pro Phe Trp Asn Lys 545 550 555 560 Asp Tyr Phe Gly
Asn Phe Tyr Gly Lys Asn Gly Val Cys Phe Pro Leu 565 570 575 Tyr Tyr
Asp Gln Thr Glu Asp Ile Gly Ser Lys Gly Tyr Ser Leu Gly 580 585 590
Ile Phe Leu Gly Val Asn Leu Leu Ala Phe Leu Ile Ile Val Phe Ser 595
600 605 Tyr Ile Thr Met Phe Cys Ser Ile Gln Lys Thr Ala Leu Gln Thr
Thr 610 615 620 Glu Val Arg Asn Cys Phe Gly Arg Glu Val Ala Val Ala
Asn Arg Phe 625 630 635 640 Phe Phe Ile Val Phe Ser Asp Ala Ile Cys
Trp Ile Pro Val Phe Val 645 650 655 Val Lys Ile Leu Ser Leu Phe Arg
Val Glu Ile Pro Asp Thr Met Thr 660 665 670 Ser Trp Ile Val Ile Phe
Phe Leu Pro Val Asn Ser Ala Leu Asn Pro 675 680 685 Ile Leu Tyr Thr
Leu Thr Thr Asn Phe Phe Lys Asp Lys Leu Lys Gln 690 695 700 Leu Leu
His Lys His Gln Arg Lys Ser Ile Phe Lys Ile Lys Lys Lys 705 710 715
720 Ser Leu Ser Thr Ser Ile Val Trp Ile Glu Asp Ser Ser Ser Leu Lys
725 730 735 Leu Gly Val Leu Asn Lys Ile Thr Leu Gly Asp Ser Ile Met
Lys Pro 740 745 750 Val Ser 3 1115 PRT H. sapiens 3 Met Ala Thr Met
Ser Gly Thr Thr Ile Val Cys Leu Ile Tyr Leu Thr 1 5 10 15 Thr Met
Leu Gly Asn Ser Gln Gly Val Asn Leu Lys Ile Glu Ser Pro 20 25 30
Ser Pro Pro Thr Leu Cys Ser Val Glu Gly Thr Phe His Cys Asp Asp 35
40 45 Gly Met Leu Gln Cys Val Leu Met Gly Ser Lys Cys Asp Gly Val
Ser 50 55 60 Asp Cys Glu Asn Gly Met Asp Glu Ser Val Glu Thr Cys
Gly Cys Leu 65 70 75 80 Gln Ser Glu Phe Gln Cys Asn His Thr Thr Cys
Ile Asp Lys Ile Leu 85 90 95 Arg Cys Asp Arg Asn Asp Asp Cys Ser
Asn Gly Leu Asp Glu Arg Glu 100 105 110 Cys Asp Ile Tyr Ile Cys Pro
Leu Gly Thr His Val Lys Trp His Asn 115 120 125 His Phe Cys Val Pro
Arg Asp Lys Gln Cys Asp Phe Leu Asp Asp Cys 130 135 140 Gly Asp Asn
Ser Asp Glu Lys Ile Cys Glu Arg Arg Glu Cys Val Ala 145 150 155 160
Thr Glu Phe Lys Cys Asn Asn Ser Gln Cys Val Ala Phe Gly Asn Leu 165
170 175 Cys Asp Gly Leu Val Asp Cys Val Asp Gly Ser Asp Glu Asp Gln
Val 180 185 190 Ala Cys Asp Ser Asp Lys Tyr Phe Gln Cys Ala Glu Gly
Ser Leu Ile 195 200 205 Lys Lys Glu Phe Val Cys Asp Gly Trp Val Asp
Cys Lys Leu Thr Phe 210 215 220 Ala Asp Glu Leu Asn Cys Lys Leu Cys
Asp Glu Asp Asp Phe Arg Cys 225 230 235 240 Ser Asp Thr Arg Cys Ile
Gln Lys Ser Asn Val Cys Asp Gly Tyr Cys 245 250 255 Asp Cys Lys Thr
Cys Asp Asp Glu Glu Val Cys Ala Asn Asn Thr Tyr 260 265 270 Gly Cys
Pro Met Asp Thr Lys Tyr Met Cys Arg Ser Ile Tyr Gly Glu 275 280 285
Pro Arg Cys Ile Asp Lys Asp Asn Val Cys Asn Met Ile Asn Asp Cys 290
295 300 Arg Asp Gly Asn Val Gly Thr Asp Glu Tyr Tyr Cys Ser Asn Asp
Ser 305 310 315 320 Glu Cys Lys Asn Phe Gln Ala Ala Met Gly Phe Phe
Tyr Cys Pro Glu 325 330 335 Glu Arg Cys Leu Ala Lys His Leu Tyr Cys
Asp Leu His Pro Asp Cys 340 345 350 Ile Asn Gly Glu Asp Glu Gln Ser
Cys Leu Ala Pro Pro Lys Cys Ser
355 360 365 Gln Asp Glu Phe Gln Cys His His Gly Lys Cys Ile Pro Ile
Ser Lys 370 375 380 Arg Cys Asp Ser Val His Asp Cys Val Asp Trp Ser
Asp Glu Met Asn 385 390 395 400 Cys Glu Asn His Gln Cys Ala Ala Asn
Met Lys Ser Cys Leu Ser Gly 405 410 415 His Cys Ile Glu Glu His Lys
Trp Cys Asn Phe His Arg Glu Cys Pro 420 425 430 Asp Gly Ser Asp Glu
Lys Asp Cys Asp Pro Arg Pro Val Cys Glu Ala 435 440 445 Asn Gln Phe
Arg Cys Lys Asn Gly Gln Cys Ile Asp Pro Leu Gln Val 450 455 460 Cys
Val Lys Gly Asp Lys Tyr Asp Gly Cys Ala Asp Gln Ser His Leu 465 470
475 480 Ile Asn Cys Ser Gln His Ile Cys Leu Glu Gly Gln Phe Arg Cys
Arg 485 490 495 Lys Ser Phe Cys Ile Asn Gln Thr Lys Val Cys Asp Gly
Thr Val Asp 500 505 510 Cys Leu Gln Gly Met Trp Asp Glu Asn Asn Cys
Arg Tyr Trp Cys Pro 515 520 525 His Gly Gln Ala Ile Cys Gln Cys Glu
Gly Val Thr Met Asp Cys Thr 530 535 540 Gly Gln Lys Leu Lys Glu Met
Pro Val Gln Gln Met Glu Glu Asp Leu 545 550 555 560 Ser Lys Leu Met
Ile Gly Asp Asn Leu Leu Asn Leu Thr Ser Thr Thr 565 570 575 Phe Ser
Ala Thr Tyr Tyr Asp Lys Val Thr Tyr Leu Asp Leu Ser Arg 580 585 590
Asn His Leu Thr Glu Ile Pro Ile Tyr Ser Phe Gln Asn Met Trp Lys 595
600 605 Leu Thr His Leu Asn Leu Ala Asp Asn Asn Ile Thr Ser Leu Lys
Asn 610 615 620 Gly Ser Leu Leu Gly Leu Ser Asn Leu Lys Gln Leu His
Ile Asn Gly 625 630 635 640 Asn Lys Ile Glu Thr Ile Glu Glu Asp Thr
Phe Ser Ser Met Ile His 645 650 655 Leu Thr Val Leu Asp Leu Ser Asn
Gln Arg Leu Thr His Val Tyr Lys 660 665 670 Asn Met Phe Lys Gly Leu
Lys Gln Ile Thr Val Leu Asn Ile Ser Arg 675 680 685 Asn Gln Ile Asn
Ser Ile Asp Asn Gly Ala Phe Asn Asn Leu Ala Asn 690 695 700 Val Arg
Leu Ile Asp Leu Ser Gly Asn Val Ile Lys Asp Ile Gly Gln 705 710 715
720 Lys Val Phe Met Gly Leu Pro Arg Leu Val Glu Leu Lys Thr Asp Ser
725 730 735 Tyr Arg Phe Cys Cys Leu Ala Pro Glu Gly Val Lys Cys Ser
Pro Lys 740 745 750 Gln Asp Glu Phe Ser Ser Cys Glu Asp Leu Met Ser
Asn His Val Leu 755 760 765 Arg Val Ser Ile Trp Val Leu Gly Val Ile
Ala Leu Val Gly Asn Phe 770 775 780 Val Val Ile Phe Trp Arg Val Arg
Asp Phe Arg Gly Gly Lys Val His 785 790 795 800 Ser Phe Leu Ile Thr
Asn Leu Ala Ile Gly Asp Phe Leu Met Gly Val 805 810 815 Tyr Leu Leu
Ile Ile Ala Thr Ala Asp Thr Tyr Tyr Arg Gly Val Tyr 820 825 830 Ile
Ser His Asp Glu Asn Trp Lys Gln Ser Gly Leu Cys Gln Phe Ala 835 840
845 Gly Phe Val Ser Thr Phe Ser Ser Glu Leu Ser Val Leu Thr Leu Ser
850 855 860 Thr Ile Thr Leu Asp Arg Leu Ile Cys Ile Leu Phe Pro Leu
Arg Arg 865 870 875 880 Thr Arg Leu Gly Leu Arg Gln Ala Ile Ile Val
Met Ser Cys Ile Trp 885 890 895 Val Leu Val Phe Leu Leu Ala Val Leu
Pro Leu Leu Gly Phe Ser Tyr 900 905 910 Phe Glu Asn Phe Tyr Gly Arg
Ser Gly Val Cys Leu Ala Leu His Val 915 920 925 Thr Pro Asp Arg Arg
Pro Gly Trp Glu Tyr Ser Val Gly Val Phe Ile 930 935 940 Leu Leu Asn
Leu Leu Ser Phe Val Leu Ile Ala Ser Ser Tyr Leu Trp 945 950 955 960
Met Phe Ser Val Ala Lys Lys Thr Arg Ser Ala Val Arg Thr Ala Glu 965
970 975 Ser Lys Asn Asp Asn Ala Met Ala Arg Arg Met Thr Leu Ile Val
Met 980 985 990 Thr Asp Phe Cys Cys Trp Val Pro Ile Ile Val Leu Gly
Phe Val Ser 995 1000 1005 Leu Ala Gly Ala Arg Ala Asp Asp Gln Val
Tyr Ala Trp Ile Ala Val 1010 1015 1020 Phe Val Leu Pro Leu Asn Ser
Ala Thr Asn Pro Val Ile Tyr Thr Leu 1025 1030 1035 1040 Ser Thr Ala
Pro Phe Leu Gly Asn Val Arg Lys Arg Ala Asn Arg Phe 1045 1050 1055
Arg Lys Ser Phe Ile His Ser Phe Thr Gly Asp Thr Lys His Ser Tyr
1060 1065 1070 Val Asp Asp Gly Thr Thr His Ser Tyr Cys Glu Lys Lys
Ser Pro Tyr 1075 1080 1085 Arg Gln Leu Glu Leu Lys Arg Leu Arg Ser
Leu Asn Ser Ser Pro Pro 1090 1095 1100 Met Tyr Tyr Asn Thr Glu Leu
His Ser Asp Ser 1105 1110 1115 4 722 PRT H. sapiens 4 Lys Cys Pro
Gly Gly Tyr Phe His Cys Asn Thr Thr Ala Gln Cys Val 1 5 10 15 Pro
Gln Arg Ala Asn Cys Asp Gly Ser Val Asp Cys Asp Asp Ala Ser 20 25
30 Asp Glu Val Asn Cys Val Asn Glu Val Asp Ala Lys Tyr Trp Asp His
35 40 45 Leu Tyr Arg Lys Gln Pro Phe Gly Arg His Asp Asn Leu Arg
Ile Gly 50 55 60 Glu Cys Leu Trp Pro Asn Glu Asn Phe Ser Cys Pro
Cys Arg Gly Asp 65 70 75 80 Glu Ile Leu Cys Arg Phe Gln Gln Leu Thr
Asp Ile Pro Glu Arg Leu 85 90 95 Pro Gln His Asp Leu Ala Thr Leu
Asp Leu Thr Gly Asn Asn Phe Glu 100 105 110 Thr Ile His Glu Thr Phe
Phe Ser Glu Leu Pro Asp Val Asp Ser Leu 115 120 125 Val Leu Lys Phe
Cys Ser Ile Arg Glu Ile Ala Ser His Ala Phe Asp 130 135 140 Arg Leu
Ala Asp Asn Pro Leu Arg Thr Leu Tyr Met Asp Asp Asn Lys 145 150 155
160 Leu Pro His Leu Pro Glu His Phe Phe Pro Glu Gly Asn Gln Leu Ser
165 170 175 Ile Leu Ile Leu Ala Arg Asn His Leu His His Leu Lys Arg
Ser Asp 180 185 190 Phe Leu Asn Leu Gln Lys Leu Gln Glu Leu Asp Leu
Arg Gly Asn Arg 195 200 205 Ile Gly Asn Phe Glu Ala Glu Val Phe Ala
Arg Leu Pro Asn Leu Glu 210 215 220 Val Leu Tyr Leu Asn Glu Asn His
Leu Lys Arg Leu Asp Pro Asp Arg 225 230 235 240 Phe Pro Arg Thr Leu
Leu Asn Leu His Thr Leu Ser Leu Ala Tyr Asn 245 250 255 Gln Ile Glu
Asp Ile Ala Ala Asn Thr Phe Pro Phe Pro Arg Leu Arg 260 265 270 Tyr
Leu Phe Leu Ala Gly Asn Arg Leu Ser His Ile Arg Asp Glu Thr 275 280
285 Phe Cys Asn Leu Ser Asn Leu Gln Gly Leu His Leu Asn Glu Asn Arg
290 295 300 Ile Glu Gly Phe Asp Leu Glu Ala Phe Ala Cys Leu Lys Asn
Leu Thr 305 310 315 320 Ser Leu Leu Leu Thr Gly Asn Arg Phe Gln Thr
Leu Asp Ser Arg Val 325 330 335 Leu Lys Asn Leu Ser Ser Leu Asp Tyr
Ile Tyr Phe Ser Trp Phe His 340 345 350 Leu Cys Ser Ala Ala Met Asn
Val Arg Val Cys Asp Pro His Gly Asp 355 360 365 Gly Ile Ser Ser Lys
Leu His Leu Leu Asp Asn Gln Ile Leu Arg Gly 370 375 380 Ser Val Trp
Val Met Ala Ser Ile Ala Val Val Gly Asn Leu Leu Val 385 390 395 400
Leu Leu Gly Arg Tyr Phe Tyr Lys Ser Arg Ser Asn Val Glu His Ser 405
410 415 Leu Tyr Leu Arg His Leu Ala Ala Ser Asp Phe Leu Met Gly Ile
Tyr 420 425 430 Leu Thr Leu Ile Ala Cys Ala Asp Ile Ser Phe Arg Gly
Glu Tyr Ile 435 440 445 Lys Tyr Glu Glu Thr Trp Arg His Ser Gly Val
Cys Ala Phe Val Gly 450 455 460 Phe Leu Ser Thr Phe Ser Cys Gln Ser
Ser Thr Leu Leu Leu Thr Leu 465 470 475 480 Val Thr Trp Asp Arg Leu
Met Ser Val Thr Arg Pro Leu Lys Pro Arg 485 490 495 Asp Thr Glu Lys
Val Arg Ile Val Leu Arg Leu Leu Leu Leu Trp Gly 500 505 510 Ile Ser
Phe Gly Leu Ala Ala Ala Pro Leu Leu Pro Asn Pro Tyr Phe 515 520 525
Gly Ser His Phe Tyr Gly Asn Asn Gly Val Cys Leu Ser Leu His Ile 530
535 540 His Asp Pro Tyr Ala Lys Gly Trp Glu Tyr Ser Ala Leu Leu Phe
Ile 545 550 555 560 Leu Val Asn Thr Leu Ser Leu Ile Phe Ile Leu Phe
Ser Tyr Ile Arg 565 570 575 Met Leu Gln Ala Ile Arg Asp Ser Gly Gly
Gly Met Arg Ser Thr His 580 585 590 Ser Gly Arg Glu Asn Val Val Ala
Thr Arg Phe Ala Ile Ile Val Thr 595 600 605 Thr Asp Cys Ala Cys Trp
Leu Pro Ile Ile Val Val Lys Leu Ala Ala 610 615 620 Leu Ser Gly Cys
Glu Ile Ser Pro Asp Leu Tyr Ala Trp Leu Ala Val 625 630 635 640 Leu
Val Leu Pro Val Asn Ser Ala Leu Asn Pro Val Leu Tyr Thr Leu 645 650
655 Thr Thr Ala Ala Phe Lys Gln Gln Leu Arg Arg Tyr Cys His Thr Leu
660 665 670 Pro Ser Cys Ser Leu Val Asn Asn Glu Thr Arg Ser Gln Thr
Gln Thr 675 680 685 Ala Tyr Glu Ser Gly Leu Ser Val Ser Leu Ala His
Leu Gly Gly Gly 690 695 700 Val Gly Gly Gly Ser Gly Arg Lys Arg Met
Ser His Arg Gln Met Ser 705 710 715 720 Tyr Leu
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