Meg-4 protein

Abstract

The present invention provides a DNA expressed at high frequency in mesangial cells and a protein (Meg-4) encoded by this DNA. These substances are useful in, for example, identifying mesangial cells and detecting abnormalities in mesangial cells. Moreover, the above protein would be helpful for clarification of the functions of mesangial cells and, in its turn, for clarification of the causes of diseases relating to mesangial cells. This protein is expectedly applicable to the treatment, diagnosis, and such of diseases relating to mesangial cells.

1 . A protein comprising the amino acid sequence of SEQ ID NO: 2, or a protein comprising the amino acid sequence of SEQ ID NO: 2 in which one or more amino acids are replaced, deleted, added, and/or inserted, and being functionally equivalent to the protein comprising the amino acid sequence of SEQ ID NO: 2.  
     
     
         2 . The protein of  claim 1 , wherein the protein comprises an amino acid sequence that has not less than 90% homology to the amino acid sequence of SEQ ID NO: 2.  
     
     
         3 . The protein of  claim 1 , wherein the protein comprises the amino acid sequence of SEQ ID NO: 2.  
     
     
         4 . A DNA encoding the protein of  claim 1 .  
     
     
         5 . The DNA of  claim 4 , wherein the DNA comprises a nucleotide sequence that has not less than 85% homology to the nucleotide sequence of SEQ ID NO: 1.  
     
     
         6 . The DNA of  claim 5 , wherein the DNA comprises a protein coding region in the nucleotide sequence of SEQ ID NO: 1.  
     
     
         7 . A DNA encoding the protein of  claim 1 , the DNA hybridizing under stringent conditions with DNA comprising a nucleotide sequence of SEQ ID NO: 1.  
     
     
         8 . A DNA hybridizing specifically with a DNA comprising the nucleotide sequence of SEQ ID NO: 1 or with the complementary strand thereof, the DNA having a chain length of at least 15 nucleotides.  
     
     
         9 . An antisense DNA against the DNA of  claim 6  or a portion thereof.  
     
     
         10 . A vector comprising the DNA of any one of  claim 4 ,  5 ,  6 , and  7 .  
     
     
         11 . A transformant expressively carrying the DNA of any one of  claim 4 ,  5 ,  6 , and  7 .  
     
     
         12 . A method for producing the protein of  claim 1 , the method comprising culturing the transformant of  claim 11  and collecting an expression product of the DNA of any one of  claim 4 ,  5 ,  6 , and  7 .  
     
     
         13 . An antibody binding to the protein of  claim 1 .  
     
     
         14 . The antibody of  claim 13 , wherein the antibody recognizes a protein comprising an amino acid sequence selected from the amino acid sequence of SEQ ID NO: 2.  
     
     
         15 . The antibody of  claim 14 , wherein the antibody is a monoclonal antibody.  
     
     
         16 . An immunoassay method for measuring the protein of  claim 3  or a fragment thereof based on immunological binding of the antibody of  claim 14  or  15  to the protein of  claim 2  or a fragment thereof.  
     
     
         17 . A reagent for an immunoassay for the protein of  claim 3  or a fragment thereof, the reagent comprising the antibody of  claim 14  or  15 .  
     
     
         18 . A method for detecting mesangial proliferative nephropathy, the method comprising measuring the protein of  claim 3  or a fragment thereof contained in a biological sample and comparing the measured value with that obtained from a normal sample.  
     
     
         19 . A transgenic nonhuman vertebrate in which the expression level of a gene encoding Meg-4 is modified.  
     
     
         20 . The transgenic nonhuman vertebrate of  claim 19 , wherein the nonhuman vertebrate is a mouse.  
     
     
         21 . The Ttransgenic nonhuman vertebrate of  claim 20 , wherein the nonhuman vertebrate is a knockout mouse in which the expression of a gene encoding Meg-4 is inhibited.