title: cDNA cloning and expression in Escherichia coli of a plasminogen activator inhibitor from human placenta.
abstract: Two nearly full-length cDNAs for placental plasminogen activator inhibitor (PAI) have been isolated from a human placenta lambda gt11 cDNA library. One positive (lambda PAI-75.1) expressed a protein that could adsorb and purify anti-PAI antibodies. The expressed protein inhibited the activity of human urokinase in a fibrin autography assay, and formed a 79-kDa (reduced) covalent complex with 125I-urokinase that could be immunoprecipitated with anti-PAI. The cDNA insert of the longer isolate (lambda PAI-75.15) consisted of 1909 base pairs, including a 5'-noncoding region of 55 base pairs, an open reading frame of 1245 base pairs, a stop codon, a 3'-noncoding region of 581 base pairs, and a poly(A) tail. The size of the mRNA was estimated to be 2.0 kilobases by Northern blot analysis. The translated amino acid sequence consisted of 415 amino acids, corresponding to a 46.6-kDa protein. The sequence was related to members of the serpin gene family, particularly ovalbumin and the chicken gene Y protein. Like these avian proteins, placental PAI appears to lack a cleavable NH2-terminal signal peptide. Residues 347-376 were identical to the partial sequence reported recently for a PAI isolated from the human monocytic U-937 cell line. Placental PAI mRNA was apparently expressed at low levels in human umbilical vein endothelial cells, but was not detectable in HepG2 hepatoma cells. It was present in U-937 cells and was inducible at least 10-fold by phorbol 12-myristate 13-acetate. Thus placental PAI is a unique member of the serpin gene family, distinct from endothelial-type PAI. It is probably identical to monocyte-macrophage PAI.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics*; D005260:Female; D005796:Genes; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D010960:Plasminogen Activators / Q000037:antagonists & inhibitors*; D015849:Plasminogen Inactivators; D011247:Pregnancy; D014176:Protein Biosynthesis; D012689:Sequence Homology, Nucleic Acid
chemical_list: D006023:Glycoproteins; D015849:Plasminogen Inactivators; D004247:DNA; D004262:DNA Restriction Enzymes; D010960:Plasminogen Activators