title: Extracellular cleavage of bullous pemphigoid antigen 180/type XVII collagen and its involvement in hemidesmosomal disassembly.
abstract: Bullous pemphigoid antigen 180 (BP180)/type XVII collagen is a transmembrane hemidesmosomal protein. Previously, we demonstrated that the collagenous ectodomain of BP180 can be cleaved within the extracellular non-collagenous (NC) 16A domain adjacent to the cell membrane and released from the cell surface. Here, we report that the BP180 cleavage is mediated by a membrane-associated metalloprotease expressed in epithelial cells. A tissue inhibitor of metalloprotease 1 (TIMP-1), but not TIMP-2, like the synthetic metalloprotease inhibitor KB-R8301, significantly reduced the cleavage. Within epithelial cells cultured for more than 36 h past confluency, antibodies to BP180 showed a reduced hemidesmosomal staining. Observed for the first time, addition of KB-R8301 to the cell culture preserved this staining. To examine the effect of the extracellular cleavage of BP180 on molecular interactions among hemidesmosomal components, we eliminated its collagenous extracellular portion, except for the NC16A domain, by collagenase digestion. Interestingly, this collagenase treatment caused partial disassembly of hemidesmosomal components in cultured human keratinocytes. Moreover, a monoclonal antibody specific for the cleaved extracellular fragment detected a unique tissue distribution of the fragment that might reflect an association of the cleavage process with the mitotic activity of epithelial tissues. Our observations demonstrate that the cleavage of BP180 occurring within the NC16A domain is mediated by a membrane-associated metalloprotease and suggest a possible involvement of the cleavage in hemidesmosomal disassembly.
authors.affiliation: Department of Dermatology, University of Würzburg, Würzburg 97080, Germany. Hirako_Y@klinik.uni-wuerzburg.de
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hirako
authors.forename: Kohichiro
authors.initials: K
authors.lastname: Yoshino
authors.forename: Detlef
authors.initials: D
authors.lastname: Zillikens
authors.forename: Katsushi
authors.initials: K
authors.lastname: Owaribe
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000494:pharmacology; D001324:Autoantigens / Q000378:metabolism* / Q000502:physiology*; D002352:Carrier Proteins; D002417:Cattle; D002460:Cell Line; D017364:Collagenases / Q000494:pharmacology; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D004847:Epithelial Cells / Q000737:chemistry; D022002:Hemidesmosomes / Q000276:immunology / Q000378:metabolism*; D045726:Metalloproteases / Q000378:metabolism / Q000502:physiology; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D011480:Protease Inhibitors / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D014018:Tissue Distribution; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000494:pharmacology; D000097805:Collagen Type XVII
chemical_list: D000911:Antibodies, Monoclonal; D001324:Autoantigens; D002352:Carrier Proteins; D017364:Collagenases; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D045726:Metalloproteases; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D011480:Protease Inhibitors; D019715:Tissue Inhibitor of Metalloproteinase-1; D000097805:Collagen Type XVII; C486268:DST protein, human