Gene originating in human chondrocyte

Abstract

This invention provides a gene specifically expressed in differentiated human chrondrocytes. By culturing the chrondrocytes in the presence of dibutyryl cAMP, the chrondrocytes are cultured in a differentiated state and any gene is searched for which has a distinction in expression between differentiated chrondrocytes and dedifferentiated chrondrocytes. This allows the gene specifically expressed in the former to be obtained.

1 . A DNA encoding a protein defined in the following (a) or (b): 
 (a) a protein comprising the amino acid sequence set forth in SEQ ID NO: 2;    (b) a protein comprising an amino acid sequence derived from the amino acid sequence set forth in SEQ ID NO: 2 by deletion or substitution of one or more amino acids therefrom, or by addition of one or more amino acids and capable of binding to nucleotide sequence CANNTG and/or nucleotide sequence CACNAG upon formation of a dimer, 
 wherein the amino acid sequence of a part of said protein corresponding to an amino acid sequence of from amino acid no. 51 to amino acid no. 108 in SEQ ID NO: 2 is provided with not less than 85% of homology to the amino acid sequence of from amino acid no. 51 to amino acid no. 108 in SEQ ID NO: 2.  
   
     
     
         2 . A DNA represented by the following (c) or (d): 
 (c) a DNA comprising a nucleotide sequence of from nucleotide no. 207 to nucleotide no. 1442 of the nucleotide sequence set forth in SEQ ID NO: 1 or a complementary nucleotide sequence thereto;    (d) a DNA capable of hybridization to the DNA defined in (c) under stringent conditions.    
     
     
         3 . A protein represented by the following (e) or (f): 
 (e) a protein comprising the amino acid sequence set forth in SEQ ID NO: 2;    (f) a protein comprising an amino acid sequence derived from the amino acid sequence set forth in SEQ ID NO: 2 by deletion or substitution of one or more amino acids therefrom, or by addition of one or more amino acids thereto and capable of binding to nucleotide sequence CANNTG and/or nucleotide sequence CACNAG upon formation of a dimer, 
 wherein the amino acid sequence of a part of said protein corresponding to an amino acid sequence of from amino acid no. 51 to amino acid no. 108 in SEQ ID NO: 2 is provided with not less than 85% of homology to the amino acid sequence of from amino acid no. 51 to amino acid no. 108 in SEQ ID NO: 2.  
   
     
     
         4 . An antibody capable of binding to the protein according to  claim 3 .  
     
     
         5 . A method for culturing human chondrocytes, which comprises monolayer-culturing the chondrocytes in the presence of a membrane-permeable cAMP analog in an amount sufficient to cause the chondrocytes to maintain a differentiated state thereof as cartilage.  
     
     
         6 . The method for culturing according to  claim 5 , wherein the membrane-permeable cAMP analog is dibutyryl cAMP.  
     
     
         7 . Human chondrocytes that have been cultured by the culturingmethod according to  claim 5  or  claim 6 , possessing the properties defined in the following (1)-(3): 
 (1) exhibiting a spherical shape and being abundant in extracellular matrix;  
 (2) capable of being satisfactorily stained with toluidine blue; and  
 (3) causing the DNA according to  claim 1  to be expressed therein.