Metalloprotease-disintegrin MDC9: Intracellular maturation and catalytic activity Journal Article

Authors: Roghani, M.; Becherer, J. D.; Moss, M. L.; Atherton, R. E.; Erdjument-Bromage, H.; Arribas, J.; Blackburn, R. K.; Weskamp, G.; Tempst, P.; Blobel, C. P.
Article Title: Metalloprotease-disintegrin MDC9: Intracellular maturation and catalytic activity
Abstract: Metalloprotease disintegrins are a family of membrane-anchored glycoproteins that are known to function in fertilization, myoblast fusion, neurogenesis, and ectodomain shedding of tumor necrosis factor (TNF)-α. Here we report the analysis of the intracellular maturation and catalytic activity of the widely expressed metalloprotease disintegrin MDC9. Our results suggest that the pro-domain of MDC9 is removed by a furin-type pro-protein convertase in the secretory pathway before the protein emerges on the cell surface. The soluble metalloprotease domain of MDC9 cleaves the insulin B-chain, a generic protease substrate, providing the first evidence that MDC9 is catalytically active. Soluble MDC9 appears to have distinct specificities for cleaving candidate substrate peptides compared with the TNF-α convertase (TACE/ADAM17). The catalytic activity of MDC9 can be inhibited by hydroxamic acid-type metalloprotease inhibitors in the low nanomolar range, in one case with up to 50-fold selectivity for MDC9 versus TACE. Peptides mimicking the predicted cysteine-switch region of MDC9 or TACE inhibit both enzymes in the low micromolar range, providing experimental evidence for regulation of metalloprotease disintegrins via a cysteine-switch mechanism. Finally, MDC9 is shown to become phosphorylated when cells are treated with the phorbol ester phorbol 12-myristate 13-acetate, a known inducer of protein ectodomain shedding. This work implies that removal of the inhibitory pro-domain of MDC9 by a furin-type pro-protein convertase in the secretory pathway is a prerequisite for protease activity. After pro-domain removal, additional steps, such as protein kinase C-dependent phosphorylation, may be involved in regulating the catalytic activity of MDC9, which is likely to target different substrates than the related TNF-α-convertase.
Keywords: controlled study; nonhuman; animal cell; animals; protease inhibitors; membrane proteins; enzyme activity; cos cells; phosphorylation; animalia; cloning, molecular; enzyme phosphorylation; protein processing; amino acid sequence; molecular sequence data; tumor necrosis factor alpha; kinetics; substrate specificity; membrane protein; hydroxamic acids; insulin; mutagenesis, site-directed; protein kinase c; catalysis; collagenases; hydrolysis; hydroxamic acid; cysteine; metalloproteinase; adam proteins; matrix metalloproteinase 1; furin; phorbol 13 acetate 12 myristate; tetradecanoylphorbol acetate; metalloproteinase inhibitor; disintegrin; disintegrins; metalloendopeptidases; humans; priority journal; article; insulin degradation
Journal Title: Journal of Biological Chemistry
Volume: 274
Issue: 6
ISSN: 0021-9258
Publisher: American Society for Biochemistry and Molecular Biology  
Date Published: 1999-02-05
Start Page: 3531
End Page: 3540
Language: English
DOI: 10.1074/jbc.274.6.3531
PUBMED: 9920899
PROVIDER: scopus
Notes: Article -- Export Date: 16 August 2016 -- Source: Scopus
Citation Impact
MSK Authors
  1. Paul J Tempst
    323 Tempst