Identification of the Second Membrane-type Matrix Metalloproteinase (MT-MMP-2) Gene from a Human Placenta cDNA Library

doi:10.1074/jbc.270.39.23013

Identification of the Second Membrane-type Matrix Metalloproteinase (MT-MMP-2) Gene from a Human Placenta cDNA Library

MT-MMPs FORM A UNIQUE MEMBRANE-TYPE SUBCLASS IN THE MMP FAMILY (*)

From the (1) Department of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920, Japan and the
(2) Department of Biochemistry, Research Institute, Fuji Chemical Industries Limited, Takaoka, Toyama 933, 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; mseiki{at}icews1.ipc.kanazawa-u.ac.jp

Abstract

Membrane-type matrix metalloproteinase (MT-MMP), which we have identified recently, is unique in its transmembrane (TM) domain at the C terminus and mediates activation of pro-gelatinase A on the cell surface (Sato, H., Takino, T., Okada, Y., Cao, J., Shinagawa, A., Yamamoto, E., and Seiki, M. (1994) Nature 370, 61-65; [Medline] Takino, T., Sato, H., Yamamoto, E., and Seiki, M.(1995) Gene (Amst.) 115, 293-298). In addition to MT-MMP, a novel MMP-related cDNA of 2.1 kilobases was isolated from a human placenta cDNA library. The cDNA contains an open reading frame for a new MMP. The deduced protein composed of 604 amino acids was closely related to MT-MMP in the amino acid sequence (66% homology at the catalytic domains) and has a potential TM domain at the C terminus. Monoclonal antibodies raised against the synthetic peptide recognized a 64-kDa protein as the major product in the transfected cells. TIMP-1 fused with the potential TM domain was localized on the cell surface while native TIMP-1 is in the culture medium. Thus, we called the second membrane-type MMP, MT-MMP-2 and renamed MT-MMP, MT-MMP-1. MT-MMP-1 and −2 are thought to form a distinct membrane-type subclass in the MMP family since all the others are secreted as soluble forms. Like MT-MMP-1, expression of MT-MMP-2 induced processing of pro-gelatinase A (68-kDa in gelatin zymography) into the activated form of 62-kDa fragments through a 64-kDa intermediate form. Expression of MT-MMP-2 mRNA was at the highest levels in the brain where MT-MMP-1 was at the lowest level compared to other tissues. MT-MMP-1 and −2 are thought to be utilized for extracellular matrix turnover on the surface of cells under different genetic controls.

Footnotes

↵^§ Supported by the Fellowships in Cancer Research of the Japan Society for Promotion of Science for Young Scientists.
↵* This work was supported in part by 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, and in part by Ciba-Geigy Foundation (Japan) for the Promotion of Science. 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:

MMPs

matrix metalloproteinases

mAb

monoclonal antibody

MT-MMP

membrane-type MMP

PCR

polymerase chain reaction

TIMP

tissue inhibitors of metalloproteinases

TM

transmembrane

DMEM

Dulbecco's modified Eagle's medium

kb

kilobase(s).
↵²T. Takino, H. Sato, A. Shinagawa, and M. Seiki, unpublished results.
- Received June 8, 1995.
- Revision received July 10, 1995.