CDNA CLONING AND CHARACTERIZATION OF A RAT SPERMATOGENESIS-ASSOCIATEDPROTEIN RSP29

RSP29, a protein secreted by rat round spermatids, stimulates the secr etory function of Sertoli cells in the testis. By making use of the N- terminal sequence homology of RSP29 and a human protein hDP1 that we h ad previously isolated, we cloned the full length cDNA sequence that e ncodes RSP29. The entire amino acid sequence of RSP29 showed significa nt homology with that of hDP1, which was later identified as glyoxalas e II. Southern analysis showed that the RSP29 protein sequence is high ly conserved in eukaryotes and possibly in prokaryotes. The RSP29 mRNA is expressed in many tissues but has an extremely high abundance in t estis. These data suggest that RSP29 may have an important function in most tissues of enkaryotic organisms. The high expression of RSP29 in testis and its stimulatory effects on Sertoli cells suggest that RSP2 9 could be especially important in the regulation of spermatogenesis. (C) 1997 Academic Press.