Mutation Analysis of Membrane Type-1 Matrix Metalloproteinase (MT1-MMP)

Abstract

MT1-MMP1 (MMP-14) is a member of a large family of zinc endoproteinases, matrixins or matrix metalloproteinases (MMPs) (1, 2). There are several structural features such as the modular domain structure and the existence of an N-terminal propeptide domain, a zinc-coordinating active site domain, and a C-terminal hemopexin-like domain that are characteristic for most MMPs (1-3). A subfamily of membrane type (MT)-MMPs including MT1-MMP is distinguished by a relatively short transmembrane domain and a cytoplasmic tail, which associate these enzymes with discrete regions of the plasma membrane and the intracellular compartment. MT1-MMP expression has been documented in many tumor cell types and strongly implicated in malignant progression (3, 4). In addition to its ability to directly cleave certain components of the extracellular matrix (5, 6), MT1-MMP initiates the activation pathway of the most widespread MMP, MMP-2, by converting pro-MMP-2 into an activation intermediate that further undergoes autocatalytic conversion to generate the mature enzyme of MMP-2 (7-9). Structure-function relationships of MT1-MMP (10 -16) and the mechanisms of pro-MMP-2 activation to the mature enzyme (9,(17)(18)(19)(20) are not understood in detail (21)(22)(23)). An immediate proximity of at least two molecules of MT1-MMP (an "activator" and a "receptor") on the cell surface is required for in trans activation of MMP-2 to the mature form (17,19,20,24). However, there is no direct biochemical evidence to support the existence of MT1-MMP oligomers on cell surfaces. In addition, mechanisms involved in activation and trafficking of MT1-MMP are not well elucidated and remain controversial (10,(13)(14)(15)(25)(26)(27)(28). Thus, furin, a serine proteinase of the trans-Golgi network, has been earlier assumed to function as a unique activator of MT1-MMP (25). However, evidence is emerging that there could be alternative pathways of 28). In this respect, it is not possible to rule out certain autocatalytic steps in MT1-MMP activation such as those involved in the activation pathway of pro-MMP-2 and pro- [29][30][31].To better understand functions of MT1-MMP, we con-* This work was supported by National Institutes of Health Grants CA83017 and CA77470, California Breast Cancer Program Grant 5JB0094, and Susan G. Komen Breast Cancer Foundation Grant 9849 (to A. Y. S.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.¶ To whom correspondence and reprint requests should be addressed: The Burnham Institute, 10901 North Torrey Pines Rd., La Jolla, CA 92037. Tel.: 858-713-6271; Fax: 858-646-3192; E-mail: strongin@ burnham.org 1 The abbreviations used are: MT, membrane type; MMP, matrix metalloproteinase; BSA, bovine serum albumin; PBS, phosphate-buffered saline; DPBS, Dulbecco's phosphate-buffered saline; DMEM, Dulbecco's modified Eagle's medium; TIMP, tissue inhibitor of me...

Furin regulates the intracellular activation and the uptake rate of cell surface-associated MT1-MMP

“…The WT/PDX cells were initially transfected with MT1-MMP and then with PDX. All of these cell lines were constructed and characterized earlier (Rozanov et al, 2001(Rozanov et al, , 2002Deryugina et al, 2004).…”

Cellular Membrane Type-1 Matrix Metalloproteinase (MT1-MMP) Cleaves C3b, an Essential Component of the Complement System

“…Cell Lines-Human breast carcinoma MCF7 cells (ATCC) stably transfected with the empty pcDNA3-zeo vector (Invitrogen) (control MCF-zeo cells) and the full-length wild type MT1-MMP (MCF-MT cells) were constructed and extensively characterized in our prior work (28). Human fibrosarcoma HT1080 cells, which synthesize MT1-MMP and MMP-2 naturally, were obtained from ATCC.…”

Membrane-type 1 Matrix Metalloproteinase Cytoplasmic Tail-binding Protein-1 Is a New Member of the Cupin Superfamily

“…The oligomerization of MT1-MMP accompanies the enhanced activation of proMMP-2 presumably by maintaining a distance appropriate for the reaction (7). Although the HPX plays the primary role in the oligomerization directly and indirectly (7,8,10), the cytoplasmic tail is also reported to contribute to the process (8,9). Thus, we examined the effect of MTCBP-1 on the activation of proMMP-2 by MT1-MMP.…”

“…Although the cytoplasmic tail is short, containing 20 amino acids, it is reported to affect functions of MT1-MMP such as the formation of oligomers (8,9), localization of the enzyme to the proteolytically active protrusions (invadopodia) (15), internalization (12,13), and cell migration and invasion (12,14). However, it has not been elucidated how the cytoplasmic tail affects these functions except for the mechanism of internalization.…”

“…Such adhesion is expected to be followed by a firmer adhesion through integrins to generate force for migration (3). At the migration edge MT1-MMP forms oligomers through the HPX domain with possible participation of the cytoplasmic tail, the hinge region, and extracellular matrix that binds to the molecule (7)(8)(9)(10). Activation of proMMP-2 by MT1-MMP is expected to be carried out efficiently within the oligomeric complex at the leading edge (7).…”