Identification and characterization of a 14 kDa human protein as a novel parvulin-like peptidyl prolyl cis/trans isomerase

a second member of the parvulin family of peptidyl-proyl cisltrans isomeras es was identified in a human lung cDNA library. The gene encoded a protein named hPar14 that has 131 amino acid residues and a molecular mass of 13676 De. Sequence comparison showed 34.5% identity to E, coli Par10 and 34% ide ntity to human Pin1 (hPar18) within a C-terminal region of 87 or 120 amino acid residues, respectively. In comparison to the E, coli Par10, hPar14 pos sesses a N-terminal extension of ill amino acid residues, This extension do es not contain a polyproline LI helix-binding motif typical of the known eu karyotic parvulins. The hPar14 does not accelerate the cis to trans interco nversion of oligopeptides with side chain-phosphorylated Ser(Thr)-Pro moiet ies as hPin1 did, In contrast, it showed preference of an arginine residue adjacent N-terminal to proline, Northern blot analysis revealed expression of the gene within various human tissues like heart, placenta, liver, kidne y and pancreas. (C) 1999 Federation of European Biochemical Societies.