Primary structure and tissue distribution of two novel proline-rich gamma-carboxyglutamic acid proteins.

ABSTRACT: Two human cDNAs that encode novel vitamin K-dependent proteins have been cloned and sequenced. The predicted amino acid sequences suggest that both are single-pass transmembrane proteins with amino-terminal gamma-carboxyglutamic acid-containing domains preceded by the typical propeptide sequences required for posttranslational gamma-carboxylation of glutamic acid residues. The polypeptides, with deduced molecular masses of 23 and 17 kDa, are proline-rich within their putative cytoplasmic domains and contain several copies of the sequences PPXY and PXXP, motifs found in a variety of signaling and cytoskeletal proteins. Accordingly, these two proteins have been called proline-rich Gla proteins (PRGP1 and PRGP2). Unlike the gamma-carboxyglutamic acid domain-containing proteins of the blood coagulation cascade, the two PRGPs are expressed in a variety of extrahepatic tissues, with PRGP1 and PRGP2 most abundantly expressed in the spinal cord and thyroid, respectively, among those tissues tested. Thus, these observations suggest a novel physiological role for these two new members of the vitamin K-dependent family of proteins.

SUBMITTER: Kulman JD 

PROVIDER: S-EPMC23027 | biostudies-literature | 1997 Aug

REPOSITORIES: biostudies-literature