Human ADAM 12 (Meltrin α) Is an Active Metalloprotease*
- From the ‡Institute of Molecular Pathology, University of Copenhagen, Denmark and the ¶Burnham Institute, La Jolla, California 92037
Abstract
The ADAMs (a disintegrinand metalloprotease) are a family of multidomain proteins with structural homology to snake venom metalloproteases. We recently described the cloning and sequencing of human ADAM 12 (meltrin α). In this report we provide evidence that the metalloprotease domain of ADAM 12 is catalytically active. We used the trapping mechanism of α2-macroglobulin to assay for protease activity of wild-type and mutant ADAM 12 proteins produced in a COS cell transfection system. We found that ADAM 12 is synthesized as a zymogen, with the prodomain maintaining the metalloprotease in a latent form, probably by means of a cysteine switch. The zymogen could be activated chemically by alkylation with N-ethylmaleimide. Cleavage of the prodomain at a site for a furin-like endopeptidase resulted in an ADAM 12 protein with proteolytic activity. The protease activity was sensitive to inhibition by 1,10-phenanthroline and could be eliminated by mutation of the critical glutamate residue at the active site. The demonstration that the ADAM 12 metalloprotease domain is functional may have important implications for future studies that explore the role of ADAM 12 protein in development and disease.
Footnotes
-
↵* This work was supported by grants from the Danish Cancer Society and the Danish Medical Research Council (to U. M. W. and R. A.). Our laboratories were also supported by the VELUX, Novo-Nordisk, Munksholm, Haensch, Thaysen, Wærum, Bojesen, Beckett, Hartmann, and Meyer Foundations (to U. M. W. and R. A.) and by the National Institutes of Health (to E. E.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
-
↵§ Supported by a fellowship from the Danish Cancer Society.
-
↵‖ To whom correspondence should be addressed: Institute of Molecular Pathology, University of Copenhagen, Frederik V’s Vej 11, DK-2100, Copenhagen, Denmark. Tel.: 45-3532-6056; Fax: 45-3532-6081; E-mail: molera{at}inet.uni-c.dk.
-
↵1 The abbreviations used are: ADAM, a disintegrin and metalloprotease; α2M, α2-macroglobulin; MMP, matrix metalloprotease; NEM,N-ethylmaleimide; SVMP, snake venom metalloprotease; nt, nucleotide(s); TACE, TNF-α-converting enzyme.
-
- Received March 10, 1998.
- Revision received April 20, 1998.
- The American Society for Biochemistry and Molecular Biology, Inc.
