title: Binding of active (57 kDa) membrane type 1-matrix metalloproteinase (MT1-MMP) to tissue inhibitor of metalloproteinase (TIMP)-2 regulates MT1-MMP processing and pro-MMP-2 activation.
abstract: Previous studies have shown that membrane type 1-matrix metalloproteinase (MT1-MMP) (MMP-14) initiates pro-MMP-2 activation in a process that is tightly regulated by the level of tissue inhibitor of metalloproteinase (TIMP)-2. However, given the difficulty in modulating TIMP-2 levels, the direct effect of TIMP-2 on MT1-MMP processing and on pro-MMP-2 activation in a cellular system could not be established. Here, recombinant vaccinia viruses encoding full-length MT1-MMP or TIMP-2 were used to express MT1-MMP alone or in combination with various levels of TIMP-2 in mammalian cells. We show that TIMP-2 regulates the amount of active MT1-MMP (57 kDa) on the cell surface whereas in the absence of TIMP-2 MT1-MMP undergoes autocatalysis to a 44-kDa form, which displays a N terminus starting at Gly(285) and hence lacks the entire catalytic domain. Neither pro-MT1-MMP (N terminus Ser(24)) nor the 44-kDa form bound TIMP-2. In contrast, active MT1-MMP (N terminus Tyr(112)) formed a complex with TIMP-2 suggesting that regulation of MT1-MMP processing is mediated by a complex of TIMP-2 with the active enzyme. Consistently, TIMP-2 enhanced the activation of pro-MMP-2 by MT1-MMP. Thus, under controlled conditions, TIMP-2 may act as a positive regulator of MT1-MMP activity by promoting the availability of active MT1-MMP on the cell surface and consequently, may support pericellular proteolysis.
authors.affiliation: Department of Pathology and Karmanos Cancer Institute, Wayne State University, Detroit, Michigan 48201, USA.
authors.forename: S
authors.initials: S
authors.lastname: Hernandez-Barrantes
authors.forename: M
authors.initials: M
authors.lastname: Toth
authors.forename: M M
authors.initials: MM
authors.lastname: Bernardo
authors.forename: M
authors.initials: M
authors.lastname: Yurkova
authors.forename: D C
authors.initials: DC
authors.lastname: Gervasi
authors.forename: Y
authors.initials: Y
authors.lastname: Raz
authors.forename: Q A
authors.initials: QA
authors.lastname: Sang
authors.forename: R
authors.initials: R
authors.lastname: Fridman
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism*; D018093:Gelatinases / Q000378:metabolism*; D000882:Haplorhini; D006367:HeLa Cells; D006801:Humans; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*; D014616:Vaccinia virus
chemical_list: D004792:Enzyme Precursors; D011994:Recombinant Proteins; D019716:Tissue Inhibitor of Metalloproteinase-2; D018093:Gelatinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; C069860:progelatinase