title: Transforming growth factor-beta induces secretion of activated ADAMTS-2. A procollagen III N-proteinase.
abstract: The metalloproteinase ADAMTS-2 has procollagen I N-proteinase activity capable of cleaving procollagens I and II N-propeptides in vitro, whereas mutations in the ADAMTS-2 gene in dermatosparaxis and Ehlers-Danlos syndrome VIIC show this enzyme to be responsible in vivo for most biosynthetic processing of procollagen I N-propeptides in skin. Yet despite its important role in the regulation of collagen deposition, information regarding regulation and substrate specificity of ADAMTS-2 has remained sparse. Here we demonstrate that ADAMTS-2 can, like the procollagen C-proteinases, be regulated by transforming growth factor-beta 1 (TGF-beta 1), with implications for mechanisms whereby this growth factor effects net increases in formation of extracellular matrix. TGF-beta 1 induced ADAMTS-2 mRNA approximately 8-fold in MG-63 osteosarcoma cells in a dose- and time-dependent, cycloheximide-inhibitable manner, which appeared to operate at the transcriptional level. Secreted ADAMTS-2 protein induced by TGF-beta 1 was 132 kDa and was identical in size to the fully processed, active form of the protease. Biosynthetic processing of ADAMTS-2 to yield the 132-kDa form is shown to be a two-step process involving sequential cleavage by furin-like convertases at two sites. Surprisingly, purified recombinant ADAMTS-2 is shown to cleave procollagen III N-propeptides as effectively as those of procollagens I and II, whereas processing of procollagen III is shown to be decreased in Ehlers-Danlos VIIC. Thus, the dogma that procollagen I and procollagen III N-proteinase activities are provided by separate enzymes appears to be false, whereas the phenotypes of dermatosparaxis and Ehlers-Danlos VIIC may arise from defects in both type I and type III collagen biosynthesis.
authors.affiliation: Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: Wei-Man
authors.initials: WM
authors.lastname: Wang
authors.forename: Seungbok
authors.initials: S
authors.lastname: Lee
authors.forename: Barry M
authors.initials: BM
authors.lastname: Steiglitz
authors.forename: Ian C
authors.initials: IC
authors.lastname: Scott
authors.forename: Carter C
authors.initials: CC
authors.lastname: Lebares
authors.forename: M Leah
authors.initials: ML
authors.lastname: Allen
authors.forename: Mitchell C
authors.initials: MC
authors.lastname: Brenner
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Takahara
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Greenspan
mesh_terms: D051722:ADAM Proteins; D000071096:ADAMTS Proteins; D000071121:ADAMTS4 Protein; D000595:Amino Acid Sequence; D015153:Blotting, Western; D003094:Collagen; D024042:Collagen Type I / Q000378:metabolism; D004535:Ehlers-Danlos Syndrome / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000201:enzymology; D005786:Gene Expression Regulation; D006031:Glycosylation; D006801:Humans; D015603:Keratinocytes / Q000201:enzymology; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation; D012516:Osteosarcoma / Q000201:enzymology; D011347:Procollagen / Q000378:metabolism; D011348:Procollagen N-Endopeptidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000378:metabolism; D012867:Skin / Q000201:enzymology; D013379:Substrate Specificity; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014407:Tumor Cells, Cultured
chemical_list: D024042:Collagen Type I; D011347:Procollagen; D011498:Protein Precursors; D012333:RNA, Messenger; D011994:Recombinant Proteins; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C032431:preprocollagen; D003094:Collagen; D051722:ADAM Proteins; D000071096:ADAMTS Proteins; C000609307:ADAMTS2 protein, human; D011348:Procollagen N-Endopeptidase; D000071121:ADAMTS4 Protein