The C-terminal Region of Membrane Type Matrix Metalloproteinase Is a Functional Transmembrane Domain Required for Pro-gelatinase A Activation (*)
- From the (1)Department of Molecular Virology and Oncology, Cancer Research Institute and the
- (2)Department of Oral Surgery, School of Medicine, Kanazawa University, Kanazawa, Ishikawa 920, Japan
- § To whom correspondence should be addressed: Dept. of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Takara-machi 13-1, Kanazawa, Ishikawa 920, Japan. Tel.: 81-762-34-4504; Fax: 81-762-60-7840.
Abstract
We identified a new matrix metalloproteinase (membrane type matrix metalloproteinase (MT-MMP)) that has a potential transmembrane (TM) domain at the C terminus and reported its expression on the surface of invasive tumor cells. The expression of MT-MMP induced specific activation of 72-kDa pro-gelatinase A (Sato, H., Takino, T., Okada, Y., Cao, J., Shinagawa, A., Yamamoto, E., and Seiki, M.(1994) Nature 370, 61-65). Thus, MT-MMP on the cell surface is thought to play an important role in various physiological and pathological processes accompanying tissue remodeling. In this study, we demonstrated that the potential TM domain deduced from the amino acid sequence functions as a membrane linker when it is fused to a secretory protein, tissue inhibitor of matrix metalloproteinases-1. The pro-gelatinase A activation function of MT-MMP was abolished by truncation of the TM domain and recovered by fusing the MT-MMP mutant with the TM domain of interleukin 2 receptor α-chain. The truncated MT-MMP was released from the cells into the medium and detected as processed or modified forms. In spite of the deletion of the TM domain some portions of the mutant MT-MMP were still retained on the surface of cells. Thus, MT-MMP has an additional device to keep it on the cell surface. The TM domain however, plays an essential role in the pro-gelatinase A activation function of MT-MMP, probably regulating its fine orientation or the localization that is necessary to interact with substrate.
Footnotes
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↵* This work was supported by the Special Coordination Fund for Promoting Science and Technology from the Ministry of Science and Technology of Japan; by a grant-in-aid for cancer research from the Ministry of Education, Science, and Culture of Japan; by the Japanese Foundation for Multidisciplinary Treatment of Cancer; and by the Foundation for Promotion of Cancer Research. 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.
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↵1 The abbreviations used are:
- MMP
-
matrix metalloproteinase
- MT-MMP
-
membrane-type matrix metalloproteinase
- TIMP-1
-
tissue inhibitor of metalloproteinases-1
- TM
-
transmembrane domain
- IL-2R
-
interleukin-2 receptor α-chain
- mAb
-
monoclonal antibody
- BSA
-
bovine serum albumin
- PBS
-
phosphate-buffered saline
- FCS
-
fetal calf serum
- DMEM
-
Dulbecco's modified Eagle's medium.
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- Received July 21, 1994.
- Revision received October 20, 1994.
- © 1995 by The American Society for Biochemistry and Molecular Biology, Inc.
