Mechanism Of Cell Surface Activation Of 72-kDa Type IV Collagenase
ISOLATION OF THE ACTIVATED FORM OF THE MEMBRANE METALLOPROTEASE (*)
- Alex Y. Strongin(§),
- Ivan Collier,
- Gregory Bannikov,
- Barry L. Marmer,
- Gregory A. Grant(1) and
- Gregory I. Goldberg
- From the Division of Dermatology Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110-1093
Abstract
Matrix metalloproteases are secreted by mammalian cells as zymogens and, upon activation, initiate tissue remodeling by proteolytic
degradation of collagens and proteoglycans. Activation of the secreted proenzymes and interaction with their specific inhibitors
determine the net enzymatic activity in the extracellular space. We have previously demonstrated that 72T4Cl can be activated
by a plasma membrane-dependent mechanism specific for this enzyme. Here, we report purification of the membrane activator
of 72T4Cl, which is a new metalloprotease identical to a recently cloned membrane-type matrix metalloprotease (MT-MMP). We
demonstrate that activated MT-MMP acts as a cell surface tissue inhibitor of metalloprotease 2 (TIMP-2) receptor with K
= 2.54 × 10
M. The activator•TlMP-2 complex in turn acts as a receptor for 72T4Cl (K
= 0.56 × 10
M), binding to the carboxyl-end domain of the enzyme. Activation of 72T4Cl on the cell membrane provides a basic mechanism
for spatially regulated extracellular proteolysis and presents a new target for prognosis and treatment of metastatic disease.
The activator, purified as a tri-molecular complex of MT-MMP•TIMP2•carboxyl-end domain of 72T4Cl, is itself an activated form
of MT-MMP, posing the following question: what is the mechanism of the activator's activation?
Footnotes
-
↵* This work was supported by National Institutes of Health Grants RO1 AR39472 and RO1 AR40618 and Training Grant T32 AR07284 and Monsanto Co./Washington University Biomedical Research Agreement. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
-
↵1 The abbreviations used are:
- ECM
-
extracellular matrix
- TIMP-1 and TIMP-2
-
tissue inhibitors of metalloproteases 1 and 2, respectively
- 92T4Cl and 72T4Cl
-
92- and 72-kDa type IV collagenase, respectively
- 26-kDa CT
-
26-kDa carboxyl-terminal fragment of 72T4Cl
- FLAG-CT
-
recombinant fusion protein of 26-kDa CT with FLAG peptide
- MT-MMP
-
membrane-type matrix metalloprotease
- PAGE
-
polyacrylamide gel electrophoresis
- TPA
-
12-O-tetradecanoyl-phorbol acetate
- BS3
-
bis(sulfosuccinimidyl) suberate.
-
↵2A. Y. Strongin, I. Collier, G. Bannikov, B. L. Marmer, G. A. Grant, and G. I. Goldberg, unpublished results.
-
- Received September 14, 1994.
- Revision received November 28, 1994.
- © 1995 by The American Society for Biochemistry and Molecular Biology, Inc.
