title: Identification and cloning of the membrane-associated serine protease, hepsin, from mouse preimplantation embryos.
abstract: Previous studies have suggested the existence of a membrane-associated serine protease expressed by mammalian preimplantation embryos. In this study, we have identified hepsin, a type II transmembrane serine protease, in early mouse blastocysts. Mouse hepsin was highly homologous to the previously identified human and rat cDNAs. Two isoforms, differing in their cytoplasmic domains, were detected. The tissue distribution of mouse hepsin was similar to that seen in humans, with prominent expression in liver and kidney. In mouse embryos, hepsin expression was observed in the two-cell stage, reached a maximal level at the early blastocyst stage, and decreased subsequent to blastocyst hatching. Expression of a soluble form of hepsin revealed its ability to autoactivate in a concentration-dependent manner. Catalytically inactive soluble hepsin was unable to autoactivate. These results suggest that hepsin may be the first serine protease expressed during mammalian development, making its ability to autoactivate critical to its function.
authors.affiliation: Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73190, USA.
authors.forename: T K
authors.initials: TK
authors.lastname: Vu
authors.forename: R W
authors.initials: RW
authors.lastname: Liu
authors.forename: C J
authors.initials: CJ
authors.lastname: Haaksma
authors.forename: J J
authors.initials: JJ
authors.lastname: Tomasek
authors.forename: E W
authors.initials: EW
authors.lastname: Howard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D046508:Culture Techniques; D047108:Embryonic Development; D005260:Female; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011247:Pregnancy; D051381:Rats; D016415:Sequence Alignment; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics*; D014018:Tissue Distribution
chemical_list: D008565:Membrane Proteins; D012697:Serine Endopeptidases; C055645:hepsin