YS68 gene involved in primitive hematopoiesis

Abstract

A novel gene, dubbed “YS68”, involved in primitive hematopoiesis was successfully isolated from cDNA derived from mouse yolk sacs. In addition, a human gene corresponding to this gene was successfully isolated. Expression characteristics of these genes suggested their involvement in primitive hematopoiesis. The proteins of this invention and genes encoding the proteins may be utilized as tools for drug development against diseases, such as hematological disorders.

What is claimed is:  
     
         1 . An isolated nucleic acid of any one of (a) to (e) below: 
 (a) a nucleic acid encoding a protein comprising the amino acid sequence of SEQ ID NO:12 or 14;    (b) a nucleic acid comprising a coding region of the nucleotide sequence of SEQ ID NO:11 or 13;    (c) a nucleic acid encoding a protein that comprises the amino acid sequence of SEQ ID NO:12 or 14 in which one or more amino acids are substituted, deleted, inserted and/or added and that is functionally equivalent to a protein consisting of the amino acid sequence of SEQ ID NO:12 or 14;    (d) a nucleic acid that hybridizes under stringent conditions with the nucleic acid consisting of the nucleotide sequence of SEQ ID NO:11 or 13, and that encodes a protein functionally equivalent to a protein consisting of the amino acid sequence of SEQ ID NO:12 or 14; and    (e) a nucleic acid encoding a protein that has at least 60% identity to the amino acid sequence of SEQ ID NO:12 or 14.    
     
     
         2 . The nucleic acid of  claim 1 , wherein the number of amino acids substituted, deleted, inserted and/or added is 50 or fewer.  
     
     
         3 . The nucleic acid of  claim 2 , wherein the number of amino acids substituted, deleted, inserted and/or added is 30 or fewer.  
     
     
         4 . The nucleic acid of  claim 3 , wherein the number of amino acids substituted, deleted, inserted and/or added is 20 or fewer.  
     
     
         5 . The nucleic acid of  claim 4 , wherein the number of amino acids substituted, deleted, inserted and/or added is 5 or fewer.  
     
     
         6 . The nucleic acid of  claim 1 , wherein if the protein comprises one or more amino acid substitutions, the substitutions are conservative amino acid substitutions.  
     
     
         7 . The nucleic acid of  claim 1 , wherein the nucleic acid encodes a fusion protein.  
     
     
         8 . The nucleic acid of  claim 7 , wherein the nucleic acid encodes a protein encoded by the nucleotide sequence of SEQ ID NO:15.  
     
     
         9 . An isolated nucleic acid encoding a protein having at least 50% sequence homology to the sequence of SEQ ID NO:12 or 14, wherein the protein regulates the development or differentiation of a hematopoietic cell.  
     
     
         10 . The nucleic acid of  claim 9 , wherein the protein has at least 70% homology to the sequence of SEQ ID NO:12 or 14.  
     
     
         11 . The nucleic acid of  claim 9 , wherein the protein has at least 90% homology to the sequence of SEQ ID NO:12 or 14.  
     
     
         12 . The nucleic acid of  claim 9 , wherein the protein has at least 95% homology to the sequence of SEQ ID NO:12 or 14.  
     
     
         13 . An isolated nucleic acid encoding the amino acid sequence of SEQ ID NO:12 or 14 or a fragment thereof.  
     
     
         14 . A polynucleotide that hybridizes with a nucleic acid consisting of the nucleotide sequence of SEQ ID NO:11 or 13 or the complementary strand thereof and that comprises at least 15 nucleotides.  
     
     
         15 . The polynucleotide of  claim 14 , wherein the nucleotide has at least 90% homology to the nucleotide sequence of SEQ ID NO:11 or 13 over at least 15 contiguous nucleotides.  
     
     
         16 . The polynucleotide of  claim 14 , wherein the nucleotide has at least 95% homology to the nucleotide sequence of SEQ ID NO:11 or 13 over at least 15 contiguous nucleotides.  
     
     
         17 . A polynucleotide comprising a sequence that is antisense to the nucleic acid of  claim 1  over at least 15 contiguous nucleotides.  
     
     
         18 . The polynucleotide of  claim 17 , wherein the antisense sequence comprises a sequence that is complementary to a translation initiation codon within SEQ ID NO:11 or 13.  
     
     
         19 . A vector into which the nucleic acid of  claim 1  is inserted.  
     
     
         20 . A vector into which the nucleic acid of  claim 13  is inserted.  
     
     
         21 . A host cell harboring the nucleic acid of  claim 1 .  
     
     
         22 . A host cell harboring the nucleic acid of  claim 13 .  
     
     
         23 . A host cell harboring the vector of  claim 19 .  
     
     
         24 . A host cell harboring the vector of  claim 20 .  
     
     
         25 . A substantially purified polypeptide encoded by the nucleic acid of  claim 1 .  
     
     
         26 . A substantially purified polypeptide encoded by the nucleic acid of  claim 13 .  
     
     
         27 . A method for producing a polypeptide, the method comprising the steps of 
 (a) culturing the host cell of  claim 23  and    (b) recovering a polypeptide expressed from the host cell or the culture supernatant thereof.    
     
     
         28 . A method for producing a polypeptide, the method comprising the steps of 
 (a) culturing the host cell of  claim 24  and    (b) recovering a polypeptide expressed from the host cell or the culture supernatant thereof.    
     
     
         29 . An antibody against the polypeptide of  claim 25 .  
     
     
         30 . An antibody against the polypeptide of  claim 26 .  
     
     
         31 . A method for screening for a compound that binds to the polypeptide of  claim 25 , the method comprising the steps of: 
 (a) contacting a test sample with the polypeptide or a partial peptide thereof,    (b) detecting a binding activity of the test sample to the polypeptide or the partial peptide thereof, and    (c) selecting a compound comprising the binding activity to the polypeptide or the partial peptide thereof.    
     
     
         32 . A method for screening for a compound that binds to the polypeptide of  claim 26 , the method comprising the steps of: 
 (a) contacting a test sample with the polypeptide or a partial peptide thereof,    (b) detecting a binding activity of the test sample to the polypeptide or the partial peptide thereof, and    (c) selecting a compound comprising the binding activity to the polypeptide or the partial peptide thereof.    
     
     
         33 . An isolated compound identified by the method of  claim 31 .  
     
     
         34 . An isolated compound identified by the method of  claim 32 .  
     
     
         35 . A compound that binds to the polypeptide of  claim 25 .  
     
     
         36 . A compound that binds to the polypeptide of  claim 26.