title: A functional prothrombin gene product is synthesized by human kidney cells.
abstract: gamma-carboxylated polypeptides were detected in the human kidney by immunohistochemistry with a monoclonal antibody (M3B) specific for gamma-carboxyglutamyl residues. An approximately 70-kDa gamma-carboxylated protein, subsequently identified as prothrombin, was isolated from the intracellular compartment of cultured human embryonic kidney (HEK293) cells by immunoaffinity chromatography on M3B-coupled resin. Immunohistochemical analyses demonstrated that prothrombin and another vitamin K-dependent protein, the growth arrest-specific protein 6, were detectable in human kidney. As in the liver, the kidney synthesizes prothrombin as a zymogen that can be cleaved by ecarin to an amidolytically active serine protease that is inhibited by hirudin. This demonstrates for the first time the de novo synthesis of a full-length, gamma-carboxylated, and functional prothrombin gene product by human kidney cells.
authors.affiliation: Department of Clinical Chemistry, Lund University, Malmö, S-205 02, Sweden.
authors.forename: L M
authors.initials: LM
authors.lastname: Stenberg
authors.forename: M A
authors.initials: MA
authors.lastname: Brown
authors.forename: E
authors.initials: E
authors.lastname: Nilsson
authors.forename: O
authors.initials: O
authors.lastname: Ljungberg
authors.forename: J
authors.initials: J
authors.lastname: Stenflo
mesh_terms: D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D010450:Endopeptidases / Q000378:metabolism; D006629:Hirudins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D007668:Kidney / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D011516:Prothrombin / Q000096:biosynthesis* / Q000302:isolation & purification; D012697:Serine Endopeptidases / Q000378:metabolism; D013997:Time Factors; D014812:Vitamin K / Q000378:metabolism; D000099255:Growth Arrest-Specific Protein 6
chemical_list: D000911:Antibodies, Monoclonal; D010450:Endopeptidases; D006629:Hirudins; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; D011516:Prothrombin; D012697:Serine Endopeptidases; D014812:Vitamin K; D000099255:Growth Arrest-Specific Protein 6; C020097:ecarin