Molecular Dissection of the Structural Machinery Underlying the Tissue-invasive Activity of Membrane Type-1 Matrix Metalloproteinase

Abstract

Membrane type-1 matrix metalloproteinase (MT1-MMP) drives cell invasion through three-dimensional (3-D) extracellular matrix (ECM) barriers dominated by type I collagen or fibrin. Based largely on analyses of its impact on cell function under two-dimensional culture conditions, MT1-MMP is categorized as a multifunctional molecule with 1) a structurally distinct, N-terminal catalytic domain; 2) a C-terminal hemopexin domain that regulates substrate recognition as well as conformation; and 3) a type I transmembrane domain whose cytosolic tail controls protease trafficking and signaling cascades. The MT1-MMP domains that subserve cell trafficking through 3-D ECM barriers in vitro or in vivo, however, remain largely undefined. Herein, we demonstrate that collagen-invasive activity is not confined strictly to the catalytic, hemopexin, transmembrane, or cytosolic domain sequences of MT1-MMP. Indeed, even a secreted collagenase supports invasion when tethered to the cell surface in the absence of the MT1-MMP hemopexin, transmembrane, and cytosolic tail domains. By contrast, the ability of MT1-MMP to support fibrin-invasive activity diverges from collagenolytic potential, and alternatively, it requires the specific participation of MT-MMP catalytic and hemopexin domains. Hence, the tissue-invasive properties of MT1-MMP are unexpectedly embedded within distinct, but parsimonious, sequences that serve to tether the requisite matrix-degradative activity to the surface of migrating cells. INTRODUCTIONNormal as well as neoplastic cells traverse interstitial tissues by mobilizing proteolytic enzymes that dissolve intervening structural barriers that are dominated by cross-linked networks of either type I collagen or fibrin (Hiraoka et al., 1998;Chun et al., 2004;Sabeh et al., 2004;Hotary et al., 2006;. Although multiple proteinases have been implicated in tissue-invasive processes, recent studies suggest that the membrane type-1 matrix metalloproteinase (MT1-MMP) plays a critical role in conferring cells with the ability to remodel and penetrate extracellular matrix (ECM) barriers in vivo (Chun et al., 2004;Sabeh et al., 2004;Filippov et al., 2005;Hotary et al., 2006;. Nonetheless, the critical structural and functional properties that imbue MT1-MMP with proinvasive activity and that distinguish it from the bulk of the Ͼ500 proteinases encoded in the mammalian genome remain largely undefined (Puente et al., 2003).Similar in its overall domain structure to the larger family of secreted MMPs, the MT1-MMP zymogen is composed of a propeptide domain, a Zn-containing catalytic domain, a flexible linker peptide, and a hemopexin-like domain near its carboxy terminus . In contrast to the secreted MMPs, however, the MT1-MMP hemopexin domain is extended to include a glutamic acid-rich stem region that connects the extracellular face of the proteinase to a single-pass transmembrane segment that terminates in a short, 20-amino acid cytosolic tail . In its membrane-tethered configuration, studies to date have largely focused on the ability...

Hic-5 mediates endothelial sprout initiation by regulating a key surface metalloproteinase

“…For this reason, we performed surface biotinylation assays, which demonstrated decreased surface expression of MT1-MMP that correlated with decreased invasion responses in the absence of Hic-5. Thus, Hic-5 silencing did not alter overall MT1-MMP activity levels, supporting that surface localization of MT1-MMP, rather than overall activity, is a key indicator of invasive behavior (Hotary et al, 2000;Yana and Weiss, 2000;Uekita et al, 2001;Egeblad and Werb, 2002;Li et al, 2008;Kwak et al, 2012). The observation that Hic-5 depletion decreased S1P-mediated MT1-MMP plasma membrane translocation in surface biotinylation assays, suggests that Hic-5 can function as a molecular adaptor to transport activated MT1-MMP to the plasma membrane for successful sprouting responses.…”

“…In addition to Hic-5, invadopodia also contain membrane type-1 matrix metalloproteinase (MT1-MMP, also known as MMP14) (Egeblad and Werb, 2002). MT1-MMP is a member of the MMP family that contains a transmembrane domain, which anchors it to the cell surface and facilitates the proximal extracellular matrix (ECM) breakdown needed for invasion into 3D matrices (Hotary et al, 2000;Yana and Weiss, 2000;Uekita et al, 2001;Egeblad and Werb, 2002;Li et al, 2008). Although multiple classes of MMPs have been implicated in angiogenic events, MT1-MMP is essential for endothelial invasion through a 3D ECM.…”

Matrix metalloproteinases 15 and 19 are stromal regulators of colorectal cancer development from the early stages

“…MMP-15 is a recently discovered membrane-type MMP (4); among the six membrane-type MMPs, only MMP-14 has been widely investigated and it is thought to play a crucial role in cellular invasion and proliferation (25). Thus, although MMP-15 is supposed to play a similar role as MMP-14 in cell invasion (9), less attention has been paid to MMP-15 and its role remains to be elucidated.…”

HOX transcription factors and the prostate tumor microenvironment

“…MMP-14 differs from other MMPs as it is membrane bound through a transmembrane domain with its catalytic center on the outside of the cell [64] . Its expression in prostate cancer cells is associated with androgen independence [65] and aggressiveness [66] .…”