U.S. patent application number 11/259417 was filed with the patent office on 2006-03-16 for organic anion transporter and gene coding for the same.
This patent application is currently assigned to Fuji Bio Medix Co., Ltd.. Invention is credited to Hitoshi Endou, Makoto Hosoyamada, Yoshikatsu Kanai, Takashi Sekine.
Application Number | 20060057677 11/259417 |
Document ID | / |
Family ID | 37814223 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060057677 |
Kind Code |
A1 |
Endou; Hitoshi ; et
al. |
March 16, 2006 |
Organic anion transporter and gene coding for the same
Abstract
A protein capable of transporting organic anions having amino
acid sequences represented by SEQ ID NO: 1 or 2 or amino acid
sequences derived therefrom by deletion, substitution or addition
of one or more amino acid residues; and a gene coding for the
protein. The protein and gene therefor are useful in vitro analysis
of drug release and drug-drug interactions and development of
methods for screening drugs useful for preventing
nephrotoxicity.
Inventors: |
Endou; Hitoshi; (Kanagawa,
JP) ; Kanai; Yoshikatsu; (Tokyo, JP) ; Sekine;
Takashi; (Tokyo, JP) ; Hosoyamada; Makoto;
(Tokyo, JP) |
Correspondence
Address: |
EDWARDS & ANGELL, LLP
P.O. BOX 55874
BOSTON
MA
02205
US
|
Assignee: |
Fuji Bio Medix Co., Ltd.
Kanagawa
JP
|
Family ID: |
37814223 |
Appl. No.: |
11/259417 |
Filed: |
October 25, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09424347 |
Jul 18, 2000 |
6986997 |
|
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PCT/JP98/02171 |
May 18, 1998 |
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11259417 |
Oct 25, 2005 |
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Current U.S.
Class: |
435/69.1 ;
435/320.1; 435/325; 530/350; 536/23.5 |
Current CPC
Class: |
C07K 14/47 20130101 |
Class at
Publication: |
435/069.1 ;
435/320.1; 435/325; 530/350; 536/023.5 |
International
Class: |
C07K 14/705 20060101
C07K014/705; C07H 21/04 20060101 C07H021/04; C12P 21/06 20060101
C12P021/06 |
Claims
1. A protein selected from (A) and (B); (A) a protein comprising
the amino acid sequence shown in SEQ ID NO 2, and (B) a protein
comprising the amino acid sequence shown in SEQ ID NO 2 deleted,
substituted or added at least one amino acid residue, and having
ability to transport organic.
2. The proteins according to claim 1, wherein said protein is
derived from human.
3. The proteins according to claim 1, wherein said protein is
derived from rats.
4. The protein according to claim 1, wherein said protein is
derived from the kidney.
5. An isolated gene encoding the protein according to claim 1.
6. An isolated gene selected from (a) and (b); (a) a DNA comprising
nucleotide sequence shown in SEQ ID NO 2, and (b) a DNA being able
to hybridize with DNA shown in SEQ ID NO 2 in stringent condition
and encoding a protein with ability to transport organic anion.
7. The gene according to claim 6, wherein said protein is derived
from human.
8. The gene according to claim 6, wherein said protein is derived
from rats.
9. The gene according to claim 6, wherein said protein is derived
from the kidney.
10. A plasmid containing regions encoding the gene according to
claims 5-9 or regions encoding the protein in said gene.
11. The plasmid according to claim 10 is expressed plasmid.
12. A host cell transformed with the plasmid according to claim
10.
13. A nucleotide comprising the partial sequence comprised of
continuous at least 14 bases shown in SEQ ID NO 2 or complementary
thereof.
14. The nucleotide according to claim 13, wherein said nucleotide
is used as a probe to detect the DNA encoding protein with ability
to transport organic anions.
15. The nucleotide according to claim 13, wherein is said
nucleotide is used to regulate an expression of proteins with
ability to transport organic anions.
Description
TECHNICAL FIELD
[0001] The present invention is related to the genes and their
encoding polypeptides, which are related to the transport of
organic anions.
BACKGROUND ART
[0002] The kidney plays important roles in the excretion of
endogenous compounds and xenobiotics. Anionic substances including
drugs are excreted via carrier-mediated pathway(s) into the urine.
The first step of this secretion is the uptake of organic anion
from the peritubular plasma across the basolateral membrane of the
proximal tubule cells.
[0003] The basolateral uptake of the organic anions has been
studied using several techniques, such as perfusion of excised
kidney, or membrane vesicles of isolated tubule cells. In these
studies, para-aminohippurate (PAH) has been widely used as a test
substrate. During these studies, it has been supposed that the
organic anion transporter responsible for the basolateral uptake of
organic anions was an organic anion/dicarboxylate exchanger.
[0004] There are, however, limitations in the previous techniques
for precise analysis of the organic anions transport, such as the
networks of transport between different transporters and the
drug-drug interaction against a single molecule. Thus, the
isolation of the organic anion transporter molecule which enables
more precise analysis of the organic anion transporter has been
eagerly awaited.
[0005] So far, several transporter molecules which are expressed in
the liver have been isolated (Hagenbuch, B. et al. Proc. Natl.
Acad. Sci. U.S.A. 88, 10629-10633, 1991, Jacquemin, E. et al. Proc.
Natl. Acad. Sci. U.S.A. 91, 133-137, 1994). The cDNA cloning of
organic cation transporter (OCT1), which is expressed in the kidney
and the liver, was also reported (Grundemann, D. et al. Nature 372,
549-52, 1994).
[0006] As a sodium-dependent dicarboxylate cotransporter, the cDNA
encoding sodium-dicarboxylate co-transporter (NaDC-1) was reported
(Pajor, A. M. J. Biol. Chem. 270, 5779-5785, 1995)
[0007] Recently, OAT-K1, an isoform of oatp was isolated (Saito, H.
et al. J. Biol. Chem. 271, 20719-20725, 1996). Oatp is organic
anion transporting polypeptide which is expressed in the liver and
mediates the sodium-independent transport of organic anions. OAT-K1
is expressed in the renal proximal tubules, however, the transport
properties of OAT-K1 was distinct from that of the organic
anion/dicarboxylate exchanger of the renal proximal tubule
cells.
DISCLOSURE OF THE INVENTION
[0008] The aim of the present invention is to provide novel genes
and the gene products, which are related to the renal transport of
organic anions. The other aims of this invention will be explained
in the following.
BRIEF EXPLANATIONS OF THE FIGURES
[0009] FIG. 1 shows the uptake of glutarate by the oocytes injected
with rat sodium dependent dicarboxylate cotransporter (rNaDC-1)
cRNA.
[0010] FIG. 2 shows the uptake experiment using the oocytes
injected with rat kidney mRNA and/or rNaDC-1 cRNA.
[0011] FIG. 3 shows Hydropathy analysis of rat organic anion
transporter OAT1.
[0012] FIG. 4 shows Northern blot analysis of rat organic anion
transporter OAT1 using mRNAs derived form various rat tissues.
[0013] FIG. 5 shows the effect of pre-incubation with glutarate, or
co-expression with rNaDC-1 was examined in oocytes injected with
rat OAT1
[0014] FIG. 6 shows the effect of extracellular sodium ion on the
rat OAT1-mediated uptake of PAH in oocytes injected with OAT1
cRNA.
[0015] FIG. 7 shows transport rate of different concentrations of
PAH in oocytes injected with rat OAT1 cRNA was examined.
[0016] FIG. 8 shows Cis-inhibitory effect of various anionic
substances on the rat OAT1-mediated uptake of PAH was examined.
[0017] FIG. 9 shows the result of that radio labeled drugs was
examined whether they were transported by rat OAT1.
BEST MODE FOR CARRYING OUT THE INVENTION
[0018] We isolated a novel cDNA which encodes a membrane protein,
OAT1, from the rat kidney. We also isolated the human homolog of
OAT1. We expressed rat and human OAT1 in the Xenopus laevis
oocytes, and successfully demonstrated that these proteins mediated
the transport of organic anions. Thus we could complete this
invention.
[0019] The proteins whose amino acid sequences are described in A,
B, C and D are all included in this invention. [0020] (A) The
protein whose amino acid sequence is shown in SEQ ID NO 1. [0021]
(B) Proteins whose amino acid sequences are identical to that shown
in SEQUENCE No. 1 except that several amino acid residues are
deleted, substituted or added in it. Despite of these changes, the
protein must possess the ability to transport organic anions.
[0022] (C) The protein whose amino acid sequence is shown in SEQ ID
NO 2. [0023] (D) Proteins whose amino acid sequences are identical
to that shown in SEQUENCE No. 2 except that several amino acid
residues are deleted, substituted or added in it. Despite of these
changes, the protein must possess the ability to transport organic
anions.
[0024] The DNAs whose nucleotide sequences are described in a, b, c
and d are also includes in this invention. [0025] (a) The DNA whose
nucleotide sequence is shown in SEQ ID NO 1. [0026] (b) DNAs which
can hybridize the DNA shown in SEQ ID NO 1 in stringent condition,
and encode the proteins possessing the ability to transport organic
anions. [0027] (c) The DNA whose nucleotide sequence is shown in
the SEQ ID NO 2. [0028] (d) DNAs which can hybridize the DNA shown
in SEQ ID NO 2 in stringent condition, and encode the proteins
possessing the ability to transport organic anions.
[0029] The novel protein of the present invention (OAT1: organic
anion transporter 1) which possesses the ability to transport
organic anions, is expressed predominantly in the renal proximal
tubule cells.
[0030] The transport rate of organic anions via OAT1, i.e. the
uptake rate of organic anions into the cell expressing OAT1, is
stimulated by dicarboxylates present in the cells. This fact
indicates that OAT1 is an organic anion/dicarboxylate exchanger.
The dicarboxylates which are effluxed in exchange for organic anion
via OAT1, are taken up by the sodium-dicarboxylate cotransporter
from the extracellular fluid. Thus, dicarboxylate are recycled for
the OAT1-mediated transport of organic anions.
[0031] The novel protein of the present invention, OAT1, possesses
the ability to transport (take up) various organic anions, such as
cycic nucleotides, prostaglandins, urate, antibiotics, diuretics
and anticancer drugs. Since chemical structures of these substances
are diverse, the substrate selectivity of OAT1 is considered to be
very wide.
[0032] The amino acid sequence of OAT1 shows no similarity to that
of the previously isolated renal organic anions transporter OAT-K1.
Thus, OAT1 belongs to distinct transporter family.
[0033] The SEQ ID NO 1 shown in the table depicts the total
nucleotide sequence of rat OAT1 cDNA (approximately 2.2 kb) with
the deduced amino acid sequence (551 amino acid residue) encoded by
the open reading frame of rat OAT1 cDNA.
[0034] The SEQ ID NO 2 shown in the table depicts the total
nucleotide sequence of human OAT1 cDNA (approximately 2.2 kb) with
the deduced amino acid sequence (563 amino acid residue) encoded by
the open reading frame of human cDNA.
[0035] We searched for the DNA database (GeneBank and EMBL) and
protein database (NBRF and SWISS-PROT) for the homologues sequence
of OAT1. We could not find any homologues sequences of OAT1 in the
sequences whose function had been clarified.
[0036] In addition to the amino acid sequence shown in SEQ ID NO 1
and NO. 2, the present invention includes the following proteins.
Proteins whose amino acid sequences are identical to that shown in
SEQ ID NO 1 except that several amino acid residues are deleted,
substituted or added in it. The extent of changes in amino acid
sequence of these proteins are acceptable when the product proteins
possess the ability to transport organic anions. Usually, numbers
of the changed amino acid residues are between one to 110,
preferably 1 to 55. These amino acid sequences show 80%, preferably
90%, identity to that shown in SEQ ID NO 1 or NO. 2.
[0037] In addition to the DNAs with the nucleotide sequences shown
in SEQUENCE NO. 1 and NO. 2, the present invention includes DNAs
which can hybridize the cDNA shown in SEQ ID NO 1 and No. 2. The
proteins encode by these DNAs must possess the ability to transport
organic anions. Usually, these DNAs show more than 70%, preferably
80%, identity to those shown in SEQ ID NO 1 or NO. 2. These DNAs
include mutated genes found in nature, artificially ? mutated genes
and the genes derived from other species of living cells.
[0038] The stringent condition in hybridization screening, which we
refer to in this invention, indicates that hybridization is
performed at 37-42.degree. C. for approximately 12 hours in
5.times.SSC (Standard Saline Citrate) solution, or in the
hybridization solution with equivalent concentrations of salts,
followed by washing in 1.times.SSC solution. If more high
stringency condition is required, washing process can be performed
in 0.1.times.SSC or solutions with equivalent concentrations of
salts.
[0039] The homologues genes encoding the organic anion transporter
of the present invention, can be obtained from other species, such
as the dogs, bovines, horses, gouts, sheep, monkeys, pigs, rabbits
and mouse, using homology screening. For this purpose, cDNA library
can be constructed from the kidney or culture cells of the aimed
species of animals.
[0040] In addition to the homology screening, the isolation of the
genes can be performed using expression cloning technique.
[0041] In the following, we will explain the method of expression
cloning briefly, which we used for the isolation of the renal
organic anion transporter. mRNA (poly (A).sup.+ RNA) obtained from
the rat kidney is divided into fractions according to their size,
and each fraction of mRNA is injected into Xenopus laevis oocytes
with cRNA of rat sodium-dependent dicarboxylate cotransporter.
[0042] The cDNA sequence of rabbit sodium dicarboxylate
cotransporter (NaDC-1) was already reported (Pajor, A. M. J. Biol.
Chem. 270, 5779-5785, 1995), therefore, the cDNA of rat sodium
dicarboxylate cotransporter (NaDC-1) can be easily isolated. The
complementary RNA (cRNA) for rNaDC-1 cDNA can be synthesized in
vitro using RNA polymerases, such as T3 or T7 RNA polymerase.
[0043] Oocytes injected with rat kidney mRNA and the cRNA of
rNaDC-1 are examined for the uptake rate of radio-labeled organic
anions, such as PAH, and the mRNA fractions showing the highest
transport rate of PAH can be determined. The cDNA library can be
constructed from these selected fractions, which should contain
concentrated mRNA for the PAH transporter. cRNAs can be synthesizes
from the constructed cDNAs and injected into oocytes with the
rNaDC-I cRNA. By repeating the screening, the cDNA which encodes
the PAH transporter can be isolated.
[0044] The sequence of the obtained clone can be determined by
dideoxytermination method, and the deduced amino acid sequence
encoded can be predicted.
[0045] Whether the cDNA obtained really encodes the organic anion
transporter can be verified as follows. cRNA synthesized from the
isolated cDNA clone is injected into Xenopus oocytes, and ability
of the expressed protein to transport of organic anions can be
examined as described elsewhere (Kanai, Y. and Hediger, M. A.
(1992) Nature 360, 467-471).
[0046] Functional analysis of the organic anion transporter, such
as the exchange property of OAT1, can be examined using the oocytes
expressing OAT1.
[0047] Using the cDNA of rat OAT1, homologues DNAs or chromosomal
genes derived from different tissues or different animals can be
obtained from appropriate cDNA or genomic library.
[0048] Based on the sequence of this invention shown in SEQ ID NO 1
and NO. 2, sets of PCR (polymerase chain reaction) primers can be
designed by which cDNA probes can be synthesized to search the cDNA
or genomic library.
[0049] cDNA library or genomic DNA library can be constructed using
methods described, for example, in "Molecular Cloning" edited by
Sambrook, J., Fritsch, E. F., and Maniatis, T. Cold Spring Harbor
Laboratory Press, 1989. Commercially available library can also be
used.
[0050] The organic anion transporter of this invention can be
produced by the molecular recombination technique. For example, the
cDNA encoding the organic anion transporter is subcloned into
expression vectors, followed by transformation p f appropriate host
cells with them. For expression systems to produce polypeptides,
host cells, such as bacteria, yeast, insect and mammalian cells can
be used. Among these, insects cells and mammalian cells are
preferable to obtain the proteins with functions.
[0051] When the organic anion transporter is required to be
expressed in the mammalian cells, the cDNA encoding the organic
anion transporter should be subcloned into mammalian expression
vectors, such as retrovirus vectors, papilloma virus vectors,
vaccinia virus vectors and SV40 vectors. In this case, the cDNA of
organic anion transporter must be inserted after? the promoter
regions, such as SV40 promoter, LTR promoter and elongation 1
.alpha. promoter. Then appropriate animal cells are transformed
with the recombinant vectors containing the organic anion
transporter cDNA. The mammalian cells, such as COS7 cells, CHO
cells, Hela cells, primary culture cells derived from the kidney,
LLC-PK1 cells and OK cells, can be used for this purpose.
[0052] The cDNAs which can be used for the above mentioned purpose
are not restricted to those shown in SEQ ID NO 1 and NO. 2. Since
each amino acid is encoded by several types of codon, cDNAs which
encode the proteins with the amino acid sequences shown in SEQ ID
NO 1 and NO. 2 can be designed based on information of codons. Any
codons, which encode the desired amino acid, can be selected, and
cDNAs inducing more efficient expression may be designed
considering the codon preference in the host cells. The designed
cDNAs can be obtained by chemical DNA synthesis, digestion and
ligation technique, and site-directed mutagenesis method. The
methods of the site directed mutagenesis are described elsewhere
(Mark, D. F., et al., Pro Nat Aca Sci, vol 81, 5662-5666, 1984)
[0053] The nucleotides which can hybridize the cDNA of OAT1 in high
stringent condition can be used as probes to detect the organic
anion transporters. In addition, they can be used to alter the
expression level of the organic anion transporter, such as
antisense-nucleotide, ribozyme and decoy. For this purpose,
continuous nucleotides more than 14 base pairs, or their
complementary nucleotide sequences can be used. If more specificity
is required, more longer fragments, for example more than 20 to 30
nucleotides sequence, can be applied.
[0054] The antibody against the organic anion transporter of this
invention can be obtained, using the fragments of the organic anion
transporter or the synthesized polypeptides with the partial
sequences which have equivalent immunochemical properties.
Polyclonal antibody can be obtained by the ordinary immunizing
method. i.e. immunize the rat or rabbit with antigen, and recover
the serum. Monoclonal antibody can be obtained by the ordinary
method such as hybridoma technique. These antibody can be used to
detect or purify the organic anion transporter
[0055] In the following, we will explain the present invention
precisely, however, this invention is not restricted to the
following description
[0056] This invention has been performed, if not indicated
otherwise, using methods described in the "Molecular Cloning"
(edited by Sambrook, J., Fritsch, E. F., and Maniatis, T., Cold
Spring Harbor Laboratory Press, 1989), or using commercially
available reagents and kits according to the manufacturer
instructions,
EXAMPLES
Example 1
Cloning of rat Organic Anion Transporter
(1) cDNA Cloning of Rat Sodium-Dicarboxylate Co-Transporter
(rNaDC-1), and the Preparation of rNaDC-1 cRNA
[0057] A non-directional cDNA library was prepared from rat kidney
poly(A).sup.+ RNA using commercially available kit (Superscript
Choice system, GIBCO BRL) and was ligated to .lamda.ZipLox EcoRI
arms (GIBCO BRL). A PCR product corresponding to nucleotides 1323
1763 of the rabbit sodium dicarboxylate transporter (NaDC-1)
(Pajor, A. M. (1995) J. Biol. Chem. 270, 5779-5785 ) was labeled
with .sup.32P-dCTP. A rat cDNA library was screened with this probe
at low stringency. Hybridization was done overnight in the
hybridization solution at 37.degree. C. and filters were washed
finally at 37.degree. C. in 0.1.times.SSC/0.1% SDS. The
hybridization solution contains 5.times.SSC, 3.times.Denhardt's
solution, 0.2% SDS, 10% dextran sulfate, 50% formamide, 0.01%
Antifoam B, 0.2 mg/ml denatured salmon sperm DNA, 2.5 mM sodium
pyrophosphate and 25 mM MES, pH 6.5. cDNA inserts in positive
.lamda.ZipLox phage were recovered in plasmid pZL1 by in vivo
excision and further subcloned into pBluescript II SK-(Stratagene)
for sequencing and in vitro transcription.
[0058] rNaDC-1 cRNA was synthesized in vitro using the rNaDC-1 cDNA
as a template.
[0059] Xenopus laevis oocyte expression studies and uptake
measurements were performed as described elsewhere (Kanai, Y. and
Hediger, M. A. (1992) Nature 360, 467-471, 1992). Defolliculated
oocytes were injected with in vitro transcribed cRNA of rNaDC-1,
and .sup.14C-glutarate uptake was examined in ND96 solution (96 mM
NaCl, 2 mM KCl, 1.8 mM CaCl2, 1 mM MgCl2, 5 mM HEPES, pH 7.4).
[0060] As shown in FIG. 1, the oocytes injected with rNaDC-1 cRNA
showed the sodium-dependent uptake of glutarate, indicating that
the isolated rNaDC-1 encodes the rat sodium-dependent dicarboxylate
cotransporter.
(2) Cloning of the Rat Renal Organic Anion Transporter OAT1.
[0061] The expression cloning of organic anion transporter 1 (OAT1)
was performed using the method described elsewhere (Kanai, Y. and
Hediger, M. A. (1992) Nature 360, 467-471, 1992)
[0062] Four hundreds .mu.g of rat kidney poly(A).sup.+ RNA was size
fractionated as described elsewhere (Kanai, Y. and Hediger, M. A.
(1992) Nature 360, 467-471, 1992) using preparative gel
electrophoresis (BIO RAD, Model 491 Prep cell).
[0063] Then we co-injected poly(A).sup.+ RNAs of each fraction
together with rNaDC-1 cRNA into oocytes. Before uptake study, the
oocytes were routinely preincubated for two hours in ND96 solution
containing 1 mM glutarate for 2 hours.
[0064] Uptake experiment was performed in oocytes injected with
poly(A).sup.+ RNAs of each fraction together with rNaDC-1 cRNA.
.sup.14C-PAH (50 .mu.M) uptake was measured in ND96 solution
without glutarate for 1 hour. In this experiment, only those
oocytes injected with both poly(A).sup.+ RNAs of each fraction and
rNaDC-1 cRNA showed significant uptake of PAH: in contrast oocytes
injected with only poly(A).sup.+ RNAs of each fraction or rNaDC-1
cRNA did not show any uptake of PAH (FIG. 2).
[0065] We determined the cRNA fractions (1.8-2.4 kilobase (kb) poly
(A).sup.+ RNA), which induced the highest PAH uptake rate when
injected with rNaDC-1 cRNA into X. oocytes. Then a directional cDNA
library was constructed from these fractions using Superscript
Plasmid system (GIBCO BRL), and was ligated into the Sal I and Not
I site of pSPORT 1. Recombinants were electroporated into Electro
Max DH10B competent cells (GIBCO BRL). Approximately 500 colonies
were grown on nitrocellulose membrane. Plasmid DNA was purified
from colonies of each plate. Capped cRNA was synthesized in vitro
after linearization of each plasmid DNA with Not I.
[0066] Then we co-injected cRNA synthesized from each filter
together with 2 ng rNaDC-1 cRNA into oocytes. When .sup.14C-PAH
uptake was detected on a particular group, it was subdivided into
several groups, and further screened.
[0067] After screening of eight thousands clones, we isolated a
single clone (OAT1), which mediated the significant uptake of
PAH.
[0068] Deleted clones obtained by Kilo-Sequence Deletion kit
(Takara, Japan) or specially synthesized oligonucleotide primers
were used for sequencing of OAT1 cDNA. OAT1 were sequenced by
dideoxytermination method using Sequenase ver. 2.0 (Amersham) or
Dye Primer Cycle Sequencing Kit (Applied Biosystems).
[0069] Then we determined the nucleotide sequence of OAT1, and
deduced the coding region of OAT1 cDNA and the amino acid sequence
encoded.
[0070] The nucleotide SEQ ID NO 1 is the sequence of OAT1
Kyte-Doolittle hydropathy analysis (Kyte, J. and Doolittle, R. F.
(1982) J. Mol. Biol. 157, 105-132) of OAT1 predicts twelve putative
membrane-spanning domains (FIG. 3). Five N-glycosylation sites are
predicted in the first hydrophilic loop. There are 4 putative
protein kinase C-dependent phosphorylation sites in the hydrophilic
loop between 6 th and 7 th transmembrane domains.
(3) The Tissue Distribution of OAT1 Analyzed by Northern Blot
[0071] The tissue distribution of OAT1 mRNA was examined. Three
.mu.g of poly (A).sup.+ RNA prepared from various rat tissues were
electrophoresed on a 1% agarose/formaldehyde gel and transferred to
a nitrocellulose filter. The filter was hybridized at 42.degree. C.
overnight in the hybridization solution with full-length OAT1 cDNA
labeled with .sup.32P-dCTP. The filter was washed finally in
0.1.times.SSC/0.1% SDS at 65.degree. C.
[0072] Under high stringency Northern blot analysis, a strong 2.4
kb mRNA band and two bands corresponding to longer transcripts (3.9
kb and 4.2 kb) were detected predominantly in the kidney (FIG. 4).
In the kidney, expression of OAT1 mRNA is strong in the cortex and
outer medulla (cortex>outer medulla) and very weak in the inner
medulla.
[0073] Upon longer exposure, a faint 2.4 kb mRNA band was detected
in the brain. No hybridization signals were obtained with mRNA
isolated from other tissues.
(4) Intrarenal Expression of OAT1 mRNA Analyzed by in situ
Hybridization
[0074] The intrarenal expression of OAT1 was examined by in situ
hybridization analysis. In situ hybridization was performed as
described elsewhere (Kanai, Y. and Hediger, M. A. (1992) Nature
360, 467-471, 1992) with some modifications. Briefly, after
perfusion fixation with 4% paraformaldehyde, rat kidney was excised
and postfixed in 4% paraformaldehyde. Five .mu.m cryostat sections
of rat kidney were used in situ hybridization.
[0075] .sup.35S-labeled sense and antisense cRNA were synthesized
from the full-length OAT1 cDNA (in pBlueScript SK-) using T7 or T3
RNA polymerase after linearization of plasmid DNA with Spe I or Xho
I, respectively. The cryosections were hybridized with the probe
overnight in the hybridization solution, and washed to a final
stringency of 0.1.times.SSC at 37.degree. C. for 30 min.
[0076] In situ hybridization of rat kidney coronal sections
revealed that OAT1 mRNA is expressed in renal cortex and outer
medulla, especially in the medullary rays of the cortex. Expression
of OAT1 was not found in the inner medulla. This overall pattern of
in situ hybridization suggests that OAT1 is most strongly expressed
in the middle portion of the proximal tubule (S2).
Example 2
Functional Characterization of Organic Anion Transporter 1
(OAT1)
(1) The Effect of the Preincubation of Glutarate on the Transport
Activity of OAT1
[0077] The effect of the preincubation of glutarate was
investigated in the uptake experiment using the oocytes expressed
with OAT1.
[0078] The uptake experiment using PAH was performed as described
in the methods of EXAMPLE 1-(2). Oocytes injected with rat OAT1
cRNA only, or both rat OAT1 and rNaDC-1 cRNA were incubated in the
ND96 solution containing .sup.14C-PAH for 1 hour after preincubated
them in the ND96 solution with and without 1 mM of glutarate.
[0079] FIG. 5 shows the dependence of OAT 1-mediated .sup.14C-PAH
uptake on the intracellular dicarboxylate (glutarate)
concentration. The rate of .sup.14C-PAH uptake by oocytes via OAT1
is increased by preincubation of the oocytes with 1 mM glutarate.
When oocytes co-expressing rNaDC-1 and OAT1 are preincubated with
glutarate, hey showed a further increase in the rate of
.sup.14C-PAH uptake. This trans-stimulative effect of glutarate
indicates that OAT1 is an organic anion/ dicarboxylate exchanger.
Control oocytes are those which were not injected with cRNA.
(2) The Sodium Dependency of the Transport Activity of OAT1
[0080] The effect of the extracellular sodium ion on the OAT1
-mediated uptake of PAH was examined.
[0081] The uptake experiment using PAH was performed as described
in the methods of EXAMPLE 2-(1). In this experiment, choline 96
solution, in which 96 mM sodium chloride was replaced with
equimolar of choline chloride, was also used in addition to ND96
solution.
[0082] As shown in FIG. 6, replacement of extracellular sodium with
choline had no effect on the rate of .sup.14C-PAH uptake,
indicating that OAT1 is a sodium independent transporter. Control
oocytes were those which were not injected with cRNA.
(3) The Kinetic Experiment
[0083] Transport rate of different concentrations of PAH via OAT1
was measured to obtain the kinetic parameters of OAT 1.
[0084] The uptake experiment using PAH was performed as described
in the methods of EXAMPLE 2-(1). .sup.14C-PAH uptake was measured
for 3 minutes. As shown in FIG. 7, OAT1-mediated PAH uptake
followed Michaelis-Menten kinetics, and the estimated Km value was
14.3.+-.2.9 .mu.M (mean.+-.s.e.m., N=3). This values is similar to
that previously reported for the basolateral organic anion
transport system (8 .mu.M) (Ullrich, K. J. and Rumrich, G. Am. J.
Physiol. 254, F453-462, 1988).
(4) The Substrate Selectivity of OAT1 Examined by Inhibition
Study
[0085] The effect of various anionic drugs on the PAH uptake in the
oocytes injected with rat OAT1 cRNA.
[0086] The uptake experiment using PAH was performed as described
in the methods of EXAMPLE 2-(1). In this experiment, 2 .mu.M of
.sup.14C-PAH uptake in oocytes injected with rat OAT1 cRNA was
measured in the ND96 solution with and without 2 mM of various
non-labeled substances.
[0087] As shown in FIG. 8, cis-Inhibitory effect was observed for
structurally unrelated drugs. Cephaloridine (a .beta.-lactam
antibiotic), nalidixic acid (an "old" quinolone), furosemide and
ethacrynic acid (diuretics), indomethacin (a nonsteroidal
anti-inflammatory drug), probenecid (an uricosuric drug) and
valproic acid (an antiepileptic drug) potently inhibited (>85%)
OAT1-mediated .sup.14C-PAH uptake. An antineoplastic drug,
methotrexate, moderately inhibited .sup.14C-PAH uptake. Endogenous
compounds, such as prostaglandin E2, cyclic-AMP, cyclic-GMP and
uric acid also inhibited .sup.14C-PAH uptake.
(5) The Substrate Selectivity of OAT1 Examined by Uptake Experiment
Using Labeled Anionic Substances
[0088] Several radio labeled compounds were examined whether they
are taken up into oocytes via OAT1.
[0089] The uptake experiment using PAH was performed as described
in the methods of EXAMPLE 2-(1). In this experiment, radio labeled
substances were used as substrates in stead of .sup.14C-PAH.
Control oocytes were those which were not injected with cRNA.
[0090] As shown in FIG. 9, .sup.3H-methotrexate, .sup.3H-cAMP,
.sup.3H-cGMP, .sup.3H-prostaglandin E2, .sup.14C-urate and
.sup.14C-'-ketoglutarate were revealed to be transported into the
oocytes expressing OAT1. In contrast, any uptake of .sup.14C-TEA
(tetraethylammonium: a representative organic cation) and
.sup.3H-taurocholic acid were not detected (data not shown).
Example 3
Cloning of the Human Organic Anion Transporter
[0091] Using rat OAT1 cDNA obtained in EXAMPLE 1-(2), human cDNA
library was screened. Human cDNA library was constructed from human
kidney poly (A)+ RNA (Clontech).
[0092] Sequence of the isolated cDNA clone (human OAT1 cDNA) was
determined according to the methods described in Example 1. The
coding region of the human OAT1 cDNA and the deduce amino acid
sequence was determined as well.
[0093] The sequence of human OAT1 in both nucleotide and amino acid
level is shown in the SEQ ID NO 2.
[0094] The sequence homology between rat OAT1 and human OAT1 was
approximately 85% and 79%, in amino acid level and nucleotide
level, respectively.
Industrial Applicability
[0095] The present invention, organic anion transporter 1 (OAT1)
and the gene encoding OAT1 , is considered to be useful to clarify
the molecular mechanisms underlying the pharmacokinetics and
toxicokinetics, such as the drug elimination and drug-drug
interaction. In addition, the screening system to identify the
nephrotoxic drugs and the way to protect kidney from such
nephrotoxic substances will be developed, since many agents causing
renal insufficiency, such as .beta.-lactam antibiotics and NSAIDs
(non-steroidal anti inflammatory drugs), have been suggested to be
transported by OAT1, and OAT1 seems to be responsible for the
accumulation of these nephrotoxicants in the kidney.
Sequence CWU 1
1
4 1 2171 DNA Rat CDS (268)...(1956) 1 gaaagctgag ctgccctgac
ccccaaagtg aggagaagct gcaagggaaa agggagggac 60 agatcaggga
gaccggggaa gaaggaggag cagccaagga ggctgctgtc cccccacaga 120
gcagctcgga ctcagctccc ggagcaaccc agctgcggag gcaacggcag tgctgctcct
180 ccagcgaagg acagcaggca ggcagacaga cagaggtcct gggactggaa
ggcctcagcc 240 cccagccact gggctgggcc tggccca atg gcc ttt aat gac
ctc ctg cag cag 294 Met Ala Phe Asn Asp Leu Leu Gln Gln 1 5 gtg ggg
ggt gtc ggc cgc ttc cag cag atc cag gtc acc ctg gtg gtc 342 Val Gly
Gly Val Gly Arg Phe Gln Gln Ile Gln Val Thr Leu Val Val 10 15 20 25
ctc ccc ctg ctc ctg atg gct tct cac aac acc ctg cag aac ttc act 390
Leu Pro Leu Leu Leu Met Ala Ser His Asn Thr Leu Gln Asn Phe Thr 30
35 40 gct gcc atc cct acc cac cac tgc cgc ccg cct gcc gat gcc aac
ctc 438 Ala Ala Ile Pro Thr His His Cys Arg Pro Pro Ala Asp Ala Asn
Leu 45 50 55 agc aag aac ggg ggg ctg gag gtc tgg ctg ccc cgg gac
agg cag ggg 486 Ser Lys Asn Gly Gly Leu Glu Val Trp Leu Pro Arg Asp
Arg Gln Gly 60 65 70 cag cct gag tcc tgc ctc cgc ttc acc tcc ccg
cag tgg gga ctg ccc 534 Gln Pro Glu Ser Cys Leu Arg Phe Thr Ser Pro
Gln Trp Gly Leu Pro 75 80 85 ttt ctc aat ggc aca gaa gcc aat ggc
aca ggg gcc aca gag ccc tgc 582 Phe Leu Asn Gly Thr Glu Ala Asn Gly
Thr Gly Ala Thr Glu Pro Cys 90 95 100 105 acc gat ggc tgg atc tat
gac aac agc acc ttc cca tct acc atc gtg 630 Thr Asp Gly Trp Ile Tyr
Asp Asn Ser Thr Phe Pro Ser Thr Ile Val 110 115 120 act gag tgg gac
ctt gtg tgc tct cac agg gcc cta cgc cag ctg gcc 678 Thr Glu Trp Asp
Leu Val Cys Ser His Arg Ala Leu Arg Gln Leu Ala 125 130 135 cag tcc
ttg tac atg gtg ggg gtg ctg ctc gga gcc atg gtg ttc ggc 726 Gln Ser
Leu Tyr Met Val Gly Val Leu Leu Gly Ala Met Val Phe Gly 140 145 150
tac ctt gca gac agg cta ggc cgc cgg aag gta ctc atc ttg aac tac 774
Tyr Leu Ala Asp Arg Leu Gly Arg Arg Lys Val Leu Ile Leu Asn Tyr 155
160 165 ctg cag aca gct gtg tca ggg acc tgc gca gcc ttc gca ccc aac
ttc 822 Leu Gln Thr Ala Val Ser Gly Thr Cys Ala Ala Phe Ala Pro Asn
Phe 170 175 180 185 ccc atc tac tgc gcc ttc cgg ctc ctc tcg ggc atg
gct ctg gct ggc 870 Pro Ile Tyr Cys Ala Phe Arg Leu Leu Ser Gly Met
Ala Leu Ala Gly 190 195 200 atc tcc ctc aac tgc atg aca ctg aat gtg
gag tgg atg ccc att cac 918 Ile Ser Leu Asn Cys Met Thr Leu Asn Val
Glu Trp Met Pro Ile His 205 210 215 aca cgg gcc tgc gtg ggc acc ttg
att ggc tat gtc tac agc ctg ggc 966 Thr Arg Ala Cys Val Gly Thr Leu
Ile Gly Tyr Val Tyr Ser Leu Gly 220 225 230 cag ttc ctc ctg gct ggt
gtg gcc tac gct gtg ccc cac tgg cgc cac 1014 Gln Phe Leu Leu Ala
Gly Val Ala Tyr Ala Val Pro His Trp Arg His 235 240 245 ctg cag cta
ctg gtc tct gcg cct ttt ttt gcc ttc ttc atc tac tcc 1062 Leu Gln
Leu Leu Val Ser Ala Pro Phe Phe Ala Phe Phe Ile Tyr Ser 250 255 260
265 tgg ttc ttc att gag tcg gcc cgc tgg cac tcc tcc tcc ggg agg ctg
1110 Trp Phe Phe Ile Glu Ser Ala Arg Trp His Ser Ser Ser Gly Arg
Leu 270 275 280 gac ctc acc ctg agg gcc ctg cag aga gtc gcc cgg atc
aat ggg aag 1158 Asp Leu Thr Leu Arg Ala Leu Gln Arg Val Ala Arg
Ile Asn Gly Lys 285 290 295 cgg gaa gaa gga gcc aaa ttg agt atg gag
gta ctc cgg gcc agt ctg 1206 Arg Glu Glu Gly Ala Lys Leu Ser Met
Glu Val Leu Arg Ala Ser Leu 300 305 310 cag aag gag ctg acc atg ggc
aaa ggc cag gca tcg gcc atg gag ctg 1254 Gln Lys Glu Leu Thr Met
Gly Lys Gly Gln Ala Ser Ala Met Glu Leu 315 320 325 ctg cgc tgc ccc
acc ctc cgc cac ctc ttc ctc tgc ctc tcc atg ctg 1302 Leu Arg Cys
Pro Thr Leu Arg His Leu Phe Leu Cys Leu Ser Met Leu 330 335 340 345
tgg ttt gcc act agc ttt gca tac tat ggg ctg gtc atg gac ctg cag
1350 Trp Phe Ala Thr Ser Phe Ala Tyr Tyr Gly Leu Val Met Asp Leu
Gln 350 355 360 ggc ttt gga gtc agc atc tac cta atc cag gtg atc ttt
ggt gct gtg 1398 Gly Phe Gly Val Ser Ile Tyr Leu Ile Gln Val Ile
Phe Gly Ala Val 365 370 375 gac ctg cct gcc aag ctt gtg ggc ttc ctt
gtc atc aac tcc ctg ggt 1446 Asp Leu Pro Ala Lys Leu Val Gly Phe
Leu Val Ile Asn Ser Leu Gly 380 385 390 cgc cgg cct gcc cag atg gct
gca ctg ctg ctg gca ggc atc tgc atc 1494 Arg Arg Pro Ala Gln Met
Ala Ala Leu Leu Leu Ala Gly Ile Cys Ile 395 400 405 ctg ctc aat ggg
gtg ata ccc cag gac cag tcc att gtc cga acc tct 1542 Leu Leu Asn
Gly Val Ile Pro Gln Asp Gln Ser Ile Val Arg Thr Ser 410 415 420 425
ctt gct gtg ctg ggg aag ggt tgt ctg gct gcc tcc ttc aac tgc atc
1590 Leu Ala Val Leu Gly Lys Gly Cys Leu Ala Ala Ser Phe Asn Cys
Ile 430 435 440 ttc ctg tat act ggg gaa ctg tat ccc aca atg atc cgg
cag aca ggc 1638 Phe Leu Tyr Thr Gly Glu Leu Tyr Pro Thr Met Ile
Arg Gln Thr Gly 445 450 455 atg gga atg ggc agc acc atg gcc cga gtg
ggc agc atc gtg agc cca 1686 Met Gly Met Gly Ser Thr Met Ala Arg
Val Gly Ser Ile Val Ser Pro 460 465 470 ctg gtg agc atg act gcc gag
ctc tac ccc tcc atg cct ctc ttc atc 1734 Leu Val Ser Met Thr Ala
Glu Leu Tyr Pro Ser Met Pro Leu Phe Ile 475 480 485 tac ggt gct gtt
cct gtg gcc gcc agc gct gtc act gtc ctc ctg cca 1782 Tyr Gly Ala
Val Pro Val Ala Ala Ser Ala Val Thr Val Leu Leu Pro 490 495 500 505
gag acc ctg ggc cag cca ctg cca gac acg gtg cag gac ctg gag agc
1830 Glu Thr Leu Gly Gln Pro Leu Pro Asp Thr Val Gln Asp Leu Glu
Ser 510 515 520 agg tgg gcc ccc act cag aaa gaa gca ggg ata tat ccc
agg aaa ggg 1878 Arg Trp Ala Pro Thr Gln Lys Glu Ala Gly Ile Tyr
Pro Arg Lys Gly 525 530 535 aaa cag acg cga cag caa caa gag cac cag
aag tat atg gtc cca ctg 1926 Lys Gln Thr Arg Gln Gln Gln Glu His
Gln Lys Tyr Met Val Pro Leu 540 545 550 cag gcc tca gca caa gag aag
aat gga ctc tgaggactga gaaggggcct 1976 Gln Ala Ser Ala Gln Glu Lys
Asn Gly Leu 555 560 tacagaaccc taaagggagg gaaggtccta caggtctccg
gccacccaca caaggaggag 2036 gaagaggaaa tggtgaccca agtgtggggg
ttgtggttca ggaaagcatc ttcccagggg 2096 tccacctccc tttataaacc
ccaccagaac cacatcatta aaaggtttga ctgcgaaaaa 2156 aaaaaaaaaa aaaaa
2171 2 563 PRT Rat 2 Met Ala Phe Asn Asp Leu Leu Gln Gln Val Gly
Gly Val Gly Arg Phe 1 5 10 15 Gln Gln Ile Gln Val Thr Leu Val Val
Leu Pro Leu Leu Leu Met Ala 20 25 30 Ser His Asn Thr Leu Gln Asn
Phe Thr Ala Ala Ile Pro Thr His His 35 40 45 Cys Arg Pro Pro Ala
Asp Ala Asn Leu Ser Lys Asn Gly Gly Leu Glu 50 55 60 Val Trp Leu
Pro Arg Asp Arg Gln Gly Gln Pro Glu Ser Cys Leu Arg 65 70 75 80 Phe
Thr Ser Pro Gln Trp Gly Leu Pro Phe Leu Asn Gly Thr Glu Ala 85 90
95 Asn Gly Thr Gly Ala Thr Glu Pro Cys Thr Asp Gly Trp Ile Tyr Asp
100 105 110 Asn Ser Thr Phe Pro Ser Thr Ile Val Thr Glu Trp Asp Leu
Val Cys 115 120 125 Ser His Arg Ala Leu Arg Gln Leu Ala Gln Ser Leu
Tyr Met Val Gly 130 135 140 Val Leu Leu Gly Ala Met Val Phe Gly Tyr
Leu Ala Asp Arg Leu Gly 145 150 155 160 Arg Arg Lys Val Leu Ile Leu
Asn Tyr Leu Gln Thr Ala Val Ser Gly 165 170 175 Thr Cys Ala Ala Phe
Ala Pro Asn Phe Pro Ile Tyr Cys Ala Phe Arg 180 185 190 Leu Leu Ser
Gly Met Ala Leu Ala Gly Ile Ser Leu Asn Cys Met Thr 195 200 205 Leu
Asn Val Glu Trp Met Pro Ile His Thr Arg Ala Cys Val Gly Thr 210 215
220 Leu Ile Gly Tyr Val Tyr Ser Leu Gly Gln Phe Leu Leu Ala Gly Val
225 230 235 240 Ala Tyr Ala Val Pro His Trp Arg His Leu Gln Leu Leu
Val Ser Ala 245 250 255 Pro Phe Phe Ala Phe Phe Ile Tyr Ser Trp Phe
Phe Ile Glu Ser Ala 260 265 270 Arg Trp His Ser Ser Ser Gly Arg Leu
Asp Leu Thr Leu Arg Ala Leu 275 280 285 Gln Arg Val Ala Arg Ile Asn
Gly Lys Arg Glu Glu Gly Ala Lys Leu 290 295 300 Ser Met Glu Val Leu
Arg Ala Ser Leu Gln Lys Glu Leu Thr Met Gly 305 310 315 320 Lys Gly
Gln Ala Ser Ala Met Glu Leu Leu Arg Cys Pro Thr Leu Arg 325 330 335
His Leu Phe Leu Cys Leu Ser Met Leu Trp Phe Ala Thr Ser Phe Ala 340
345 350 Tyr Tyr Gly Leu Val Met Asp Leu Gln Gly Phe Gly Val Ser Ile
Tyr 355 360 365 Leu Ile Gln Val Ile Phe Gly Ala Val Asp Leu Pro Ala
Lys Leu Val 370 375 380 Gly Phe Leu Val Ile Asn Ser Leu Gly Arg Arg
Pro Ala Gln Met Ala 385 390 395 400 Ala Leu Leu Leu Ala Gly Ile Cys
Ile Leu Leu Asn Gly Val Ile Pro 405 410 415 Gln Asp Gln Ser Ile Val
Arg Thr Ser Leu Ala Val Leu Gly Lys Gly 420 425 430 Cys Leu Ala Ala
Ser Phe Asn Cys Ile Phe Leu Tyr Thr Gly Glu Leu 435 440 445 Tyr Pro
Thr Met Ile Arg Gln Thr Gly Met Gly Met Gly Ser Thr Met 450 455 460
Ala Arg Val Gly Ser Ile Val Ser Pro Leu Val Ser Met Thr Ala Glu 465
470 475 480 Leu Tyr Pro Ser Met Pro Leu Phe Ile Tyr Gly Ala Val Pro
Val Ala 485 490 495 Ala Ser Ala Val Thr Val Leu Leu Pro Glu Thr Leu
Gly Gln Pro Leu 500 505 510 Pro Asp Thr Val Gln Asp Leu Glu Ser Arg
Trp Ala Pro Thr Gln Lys 515 520 525 Glu Ala Gly Ile Tyr Pro Arg Lys
Gly Lys Gln Thr Arg Gln Gln Gln 530 535 540 Glu His Gln Lys Tyr Met
Val Pro Leu Gln Ala Ser Ala Gln Glu Lys 545 550 555 560 Asn Gly Leu
3 2171 DNA Human CDS (268)...(1956) 3 gaaagctgag ctgccctgac
ccccaaagtg aggagaagct gcaagggaaa agggagggac 60 agatcaggga
gaccggggaa gaaggaggag cagccaagga ggctgctgtc cccccacaga 120
gcagctcgga ctcagctccc ggagcaaccc agctgcggag gcaacggcag tgctgctcct
180 ccagcgaagg acagcaggca ggcagacaga cagaggtcct gggactggaa
ggcctcagcc 240 cccagccact gggctgggcc tggccca atg gcc ttt aat gac
ctc ctg cag cag 294 Met Ala Phe Asn Asp Leu Leu Gln Gln 1 5 gtg ggg
ggt gtc ggc cgc ttc cag cag atc cag gtc acc ctg gtg gtc 342 Val Gly
Gly Val Gly Arg Phe Gln Gln Ile Gln Val Thr Leu Val Val 10 15 20 25
ctc ccc ctg ctc ctg atg gct tct cac aac acc ctg cag aac ttc act 390
Leu Pro Leu Leu Leu Met Ala Ser His Asn Thr Leu Gln Asn Phe Thr 30
35 40 gct gcc atc cct acc cac cac tgc cgc ccg cct gcc gat gcc aac
ctc 438 Ala Ala Ile Pro Thr His His Cys Arg Pro Pro Ala Asp Ala Asn
Leu 45 50 55 agc aag aac ggg ggg ctg gag gtc tgg ctg ccc cgg gac
agg cag ggg 486 Ser Lys Asn Gly Gly Leu Glu Val Trp Leu Pro Arg Asp
Arg Gln Gly 60 65 70 cag cct gag tcc tgc ctc cgc ttc acc tcc ccg
cag tgg gga ctg ccc 534 Gln Pro Glu Ser Cys Leu Arg Phe Thr Ser Pro
Gln Trp Gly Leu Pro 75 80 85 ttt ctc aat ggc aca gaa gcc aat ggc
aca ggg gcc aca gag ccc tgc 582 Phe Leu Asn Gly Thr Glu Ala Asn Gly
Thr Gly Ala Thr Glu Pro Cys 90 95 100 105 acc gat ggc tgg atc tat
gac aac agc acc ttc cca tct acc atc gtg 630 Thr Asp Gly Trp Ile Tyr
Asp Asn Ser Thr Phe Pro Ser Thr Ile Val 110 115 120 act gag tgg gac
ctt gtg tgc tct cac agg gcc cta cgc cag ctg gcc 678 Thr Glu Trp Asp
Leu Val Cys Ser His Arg Ala Leu Arg Gln Leu Ala 125 130 135 cag tcc
ttg tac atg gtg ggg gtg ctg ctc gga gcc atg gtg ttc ggc 726 Gln Ser
Leu Tyr Met Val Gly Val Leu Leu Gly Ala Met Val Phe Gly 140 145 150
tac ctt gca gac agg cta ggc cgc cgg aag gta ctc atc ttg aac tac 774
Tyr Leu Ala Asp Arg Leu Gly Arg Arg Lys Val Leu Ile Leu Asn Tyr 155
160 165 ctg cag aca gct gtg tca ggg acc tgc gca gcc ttc gca ccc aac
ttc 822 Leu Gln Thr Ala Val Ser Gly Thr Cys Ala Ala Phe Ala Pro Asn
Phe 170 175 180 185 ccc atc tac tgc gcc ttc cgg ctc ctc tcg ggc atg
gct ctg gct ggc 870 Pro Ile Tyr Cys Ala Phe Arg Leu Leu Ser Gly Met
Ala Leu Ala Gly 190 195 200 atc tcc ctc aac tgc atg aca ctg aat gtg
gag tgg atg ccc att cac 918 Ile Ser Leu Asn Cys Met Thr Leu Asn Val
Glu Trp Met Pro Ile His 205 210 215 aca cgg gcc tgc gtg ggc acc ttg
att ggc tat gtc tac agc ctg ggc 966 Thr Arg Ala Cys Val Gly Thr Leu
Ile Gly Tyr Val Tyr Ser Leu Gly 220 225 230 cag ttc ctc ctg gct ggt
gtg gcc tac gct gtg ccc cac tgg cgc cac 1014 Gln Phe Leu Leu Ala
Gly Val Ala Tyr Ala Val Pro His Trp Arg His 235 240 245 ctg cag cta
ctg gtc tct gcg cct ttt ttt gcc ttc ttc atc tac tcc 1062 Leu Gln
Leu Leu Val Ser Ala Pro Phe Phe Ala Phe Phe Ile Tyr Ser 250 255 260
265 tgg ttc ttc att gag tcg gcc cgc tgg cac tcc tcc tcc ggg agg ctg
1110 Trp Phe Phe Ile Glu Ser Ala Arg Trp His Ser Ser Ser Gly Arg
Leu 270 275 280 gac ctc acc ctg agg gcc ctg cag aga gtc gcc cgg atc
aat ggg aag 1158 Asp Leu Thr Leu Arg Ala Leu Gln Arg Val Ala Arg
Ile Asn Gly Lys 285 290 295 cgg gaa gaa gga gcc aaa ttg agt atg gag
gta ctc cgg gcc agt ctg 1206 Arg Glu Glu Gly Ala Lys Leu Ser Met
Glu Val Leu Arg Ala Ser Leu 300 305 310 cag aag gag ctg acc atg ggc
aaa ggc cag gca tcg gcc atg gag ctg 1254 Gln Lys Glu Leu Thr Met
Gly Lys Gly Gln Ala Ser Ala Met Glu Leu 315 320 325 ctg cgc tgc ccc
acc ctc cgc cac ctc ttc ctc tgc ctc tcc atg ctg 1302 Leu Arg Cys
Pro Thr Leu Arg His Leu Phe Leu Cys Leu Ser Met Leu 330 335 340 345
tgg ttt gcc act agc ttt gca tac tat ggg ctg gtc atg gac ctg cag
1350 Trp Phe Ala Thr Ser Phe Ala Tyr Tyr Gly Leu Val Met Asp Leu
Gln 350 355 360 ggc ttt gga gtc agc atc tac cta atc cag gtg atc ttt
ggt gct gtg 1398 Gly Phe Gly Val Ser Ile Tyr Leu Ile Gln Val Ile
Phe Gly Ala Val 365 370 375 gac ctg cct gcc aag ctt gtg ggc ttc ctt
gtc atc aac tcc ctg ggt 1446 Asp Leu Pro Ala Lys Leu Val Gly Phe
Leu Val Ile Asn Ser Leu Gly 380 385 390 cgc cgg cct gcc cag atg gct
gca ctg ctg ctg gca ggc atc tgc atc 1494 Arg Arg Pro Ala Gln Met
Ala Ala Leu Leu Leu Ala Gly Ile Cys Ile 395 400 405 ctg ctc aat ggg
gtg ata ccc cag gac cag tcc att gtc cga acc tct 1542 Leu Leu Asn
Gly Val Ile Pro Gln Asp Gln Ser Ile Val Arg Thr Ser 410 415 420 425
ctt gct gtg ctg ggg aag ggt tgt ctg gct gcc tcc ttc aac tgc atc
1590 Leu Ala Val Leu Gly Lys Gly Cys Leu Ala Ala Ser Phe Asn Cys
Ile 430 435 440 ttc ctg tat act ggg gaa ctg tat ccc aca atg atc cgg
cag aca ggc 1638 Phe Leu Tyr Thr Gly Glu Leu Tyr Pro Thr Met Ile
Arg Gln Thr Gly 445 450 455 atg gga atg ggc agc acc atg gcc cga gtg
ggc agc atc gtg agc cca 1686 Met Gly Met Gly Ser Thr Met Ala Arg
Val Gly Ser Ile Val Ser Pro 460 465 470 ctg gtg agc atg act gcc gag
ctc tac ccc tcc atg cct ctc ttc atc 1734 Leu Val Ser Met Thr Ala
Glu Leu Tyr Pro Ser Met Pro Leu Phe Ile 475 480 485 tac ggt gct gtt
cct gtg gcc gcc agc gct gtc act gtc ctc ctg cca 1782 Tyr Gly Ala
Val Pro Val Ala Ala Ser Ala Val Thr Val Leu Leu Pro 490 495 500 505
gag acc ctg ggc cag cca ctg cca gac acg gtg cag gac ctg gag agc
1830 Glu Thr
Leu Gly Gln Pro Leu Pro Asp Thr Val Gln Asp Leu Glu Ser 510 515 520
agg tgg gcc ccc act cag aaa gaa gca ggg ata tat ccc agg aaa ggg
1878 Arg Trp Ala Pro Thr Gln Lys Glu Ala Gly Ile Tyr Pro Arg Lys
Gly 525 530 535 aaa cag acg cga cag caa caa gag cac cag aag tat atg
gtc cca ctg 1926 Lys Gln Thr Arg Gln Gln Gln Glu His Gln Lys Tyr
Met Val Pro Leu 540 545 550 cag gcc tca gca caa gag aag aat gga ctc
tgaggactga gaaggggcct 1976 Gln Ala Ser Ala Gln Glu Lys Asn Gly Leu
555 560 tacagaaccc taaagggagg gaaggtccta caggtctccg gccacccaca
caaggaggag 2036 gaagaggaaa tggtgaccca agtgtggggg ttgtggttca
ggaaagcatc ttcccagggg 2096 tccacctccc tttataaacc ccaccagaac
cacatcatta aaaggtttga ctgcgaaaaa 2156 aaaaaaaaaa aaaaa 2171 4 563
PRT Human 4 Met Ala Phe Asn Asp Leu Leu Gln Gln Val Gly Gly Val Gly
Arg Phe 1 5 10 15 Gln Gln Ile Gln Val Thr Leu Val Val Leu Pro Leu
Leu Leu Met Ala 20 25 30 Ser His Asn Thr Leu Gln Asn Phe Thr Ala
Ala Ile Pro Thr His His 35 40 45 Cys Arg Pro Pro Ala Asp Ala Asn
Leu Ser Lys Asn Gly Gly Leu Glu 50 55 60 Val Trp Leu Pro Arg Asp
Arg Gln Gly Gln Pro Glu Ser Cys Leu Arg 65 70 75 80 Phe Thr Ser Pro
Gln Trp Gly Leu Pro Phe Leu Asn Gly Thr Glu Ala 85 90 95 Asn Gly
Thr Gly Ala Thr Glu Pro Cys Thr Asp Gly Trp Ile Tyr Asp 100 105 110
Asn Ser Thr Phe Pro Ser Thr Ile Val Thr Glu Trp Asp Leu Val Cys 115
120 125 Ser His Arg Ala Leu Arg Gln Leu Ala Gln Ser Leu Tyr Met Val
Gly 130 135 140 Val Leu Leu Gly Ala Met Val Phe Gly Tyr Leu Ala Asp
Arg Leu Gly 145 150 155 160 Arg Arg Lys Val Leu Ile Leu Asn Tyr Leu
Gln Thr Ala Val Ser Gly 165 170 175 Thr Cys Ala Ala Phe Ala Pro Asn
Phe Pro Ile Tyr Cys Ala Phe Arg 180 185 190 Leu Leu Ser Gly Met Ala
Leu Ala Gly Ile Ser Leu Asn Cys Met Thr 195 200 205 Leu Asn Val Glu
Trp Met Pro Ile His Thr Arg Ala Cys Val Gly Thr 210 215 220 Leu Ile
Gly Tyr Val Tyr Ser Leu Gly Gln Phe Leu Leu Ala Gly Val 225 230 235
240 Ala Tyr Ala Val Pro His Trp Arg His Leu Gln Leu Leu Val Ser Ala
245 250 255 Pro Phe Phe Ala Phe Phe Ile Tyr Ser Trp Phe Phe Ile Glu
Ser Ala 260 265 270 Arg Trp His Ser Ser Ser Gly Arg Leu Asp Leu Thr
Leu Arg Ala Leu 275 280 285 Gln Arg Val Ala Arg Ile Asn Gly Lys Arg
Glu Glu Gly Ala Lys Leu 290 295 300 Ser Met Glu Val Leu Arg Ala Ser
Leu Gln Lys Glu Leu Thr Met Gly 305 310 315 320 Lys Gly Gln Ala Ser
Ala Met Glu Leu Leu Arg Cys Pro Thr Leu Arg 325 330 335 His Leu Phe
Leu Cys Leu Ser Met Leu Trp Phe Ala Thr Ser Phe Ala 340 345 350 Tyr
Tyr Gly Leu Val Met Asp Leu Gln Gly Phe Gly Val Ser Ile Tyr 355 360
365 Leu Ile Gln Val Ile Phe Gly Ala Val Asp Leu Pro Ala Lys Leu Val
370 375 380 Gly Phe Leu Val Ile Asn Ser Leu Gly Arg Arg Pro Ala Gln
Met Ala 385 390 395 400 Ala Leu Leu Leu Ala Gly Ile Cys Ile Leu Leu
Asn Gly Val Ile Pro 405 410 415 Gln Asp Gln Ser Ile Val Arg Thr Ser
Leu Ala Val Leu Gly Lys Gly 420 425 430 Cys Leu Ala Ala Ser Phe Asn
Cys Ile Phe Leu Tyr Thr Gly Glu Leu 435 440 445 Tyr Pro Thr Met Ile
Arg Gln Thr Gly Met Gly Met Gly Ser Thr Met 450 455 460 Ala Arg Val
Gly Ser Ile Val Ser Pro Leu Val Ser Met Thr Ala Glu 465 470 475 480
Leu Tyr Pro Ser Met Pro Leu Phe Ile Tyr Gly Ala Val Pro Val Ala 485
490 495 Ala Ser Ala Val Thr Val Leu Leu Pro Glu Thr Leu Gly Gln Pro
Leu 500 505 510 Pro Asp Thr Val Gln Asp Leu Glu Ser Arg Trp Ala Pro
Thr Gln Lys 515 520 525 Glu Ala Gly Ile Tyr Pro Arg Lys Gly Lys Gln
Thr Arg Gln Gln Gln 530 535 540 Glu His Gln Lys Tyr Met Val Pro Leu
Gln Ala Ser Ala Gln Glu Lys 545 550 555 560 Asn Gly Leu
* * * * *