Pro-collagenase-1 (Matrix Metalloproteinase-1) Binds the α2β1 Integrin upon Release from Keratinocytes Migrating on Type I Collagen

Abstract

In injured skin, collagenase-1 (matrix metalloproteinase-1 (MMP-1)) is induced in migrating keratinocytes. This site-specific expression is regulated by binding of the ␣ 2 ␤ 1 integrin with dermal type I collagen, and the catalytic activity of MMP-1 is required for keratinocyte migration. Because of this functional association among substrate/ligand, receptor, and proteinase, we assessed whether the integrin also directs the compartmentalization of MMP-1 to its matrix target. Indeed, pro-MMP-1 co-localized to sites of ␣ 2 ␤ 1 contacts in migrating keratinocytes. Furthermore, pro-MMP-1 co-immunoprecipitated with ␣ 2 ␤ 1 from keratinocytes, and ␣ 2 ␤ 1 co-immunoprecipitated with pro-MMP-1. No other MMPs bound ␣ 2 ␤ 1 , and no other integrins interacted with MMP-1. Pro-MMP-1 also provided a substrate for ␣ 2 ␤ 1 -dependent adhesion of platelets. Complex formation on keratinocytes was most efficient on native type I collagen and reduced or ablated on denatured or cleaved collagen. Competition studies suggested that the ␣ 2 I domain interacts with the linker and hemopexin domains of pro-MMP-1, not with the pro-domain. These data indicate that the interaction of pro-MMP-1 with ␣ 2 ␤ 1 confines this proteinase to points of cell contact with collagen and that the ternary complex of integrin, enzyme, and substrate function together to drive and regulate keratinocyte migration.Cells, either resting or activated, use a variety of surface receptors to sense the presence and location of specific molecules in the extracellular space. For example, integrin-ligand interactions tell cells which structural proteins they have encountered in the extracellular space, and in turn, these contacts activate signaling pathways involved in differentiation, proliferation, and gene expression, among other processes. During migration, cells need to proteolyze, to some extent, nearby extracellular matrix proteins, and hence, cell-matrix contacts can also instruct cells which proteinases are needed and where the enzyme should be targeted and released.An example of cell-matrix-mediated spatial regulation of proteolysis is seen with collagenase-1 (MMP-1), 1 a matrix metalloproteinase, in human cutaneous wounds. In response to injury, collagenase-1 is induced in basal epidermal cells (keratinocytes) as the cells move off of the basement membrane and contact native type I collagen in the underlying dermis (1), and this inductive response is specifically controlled by the collagen-binding integrin ␣ 2 ␤ 1 (2). As we demonstrated in various experiments, the catalytic activity of collagenase-1 is required and sufficient for keratinocyte migration on complex matrices containing type I collagen. For example, keratinocytes plated on mutant, collagenase-resistant type I collagen do not migrate, even in the presence of fibronectin and vitronectin; yet they express MMP-1 at levels equivalent to those released by cells on wild-type collagen (2). Keratinocyte migration is also completely inhibited by anti-collagenase-1 antibodies, which block the catalytic a...

Gelatinase-mediated migration and invasion of cancer cells

“…A favourable outcome could not only be obtained by peptides that inhibit catalytic activity of the gelatinases such as the CTT and PPC peptides, but also with the DDGW and CRV peptides, which block cell surface interactions of the gelatinases. Our results provide further evidence for the previous reports indicating a critical role of pericellular MMP activity in cell migration (Brooks et al, 1998;Brooks et al, 1996;Dumin et al, 2001). A hypothetical model of gelatinase-mediated cell migration/invasion machinery can be proposed based on these findings ( Figure 9).…”

“…It was initially observed that antibodies blocking α 5 β 1 integrin-mediated adhesion induced MMP expression in fibroblasts (Werb et al, 1989). Later studies revealed that integrin-mediated signals are general regulators of MMP expression, as α 2 β 1 integrin regulates MMP-1 expression (Riikonen et al, 1995;Dumin et al, 2001), antibodies to α 3 β 1 integrin-tetraspanin complexes induce MMP-2 expression (Sugiura and Berditchevski, 1999), and α M β 2 and α 3 β 1 integrin ligation stimulates MMP-9 expression (Wize et al, 1998;Larjava et al, 1993). The effects on MMP expression are very specific.…”

Matrix Metalloproteinase-1 Associates with Intracellular Organelles and Confers Resistance to Lamin A/C Degradation during Apoptosis

“…5,6 For more than 4 decades after the first description of MMP-1 as an interstitial collagenase, 27 many reports have shown that this matrix-degrading enzyme may be found highly expressed in inflammatory and tumoral tissues, 2-4 but very little or no importance has been given to observations that this MMP may be found intracellularly. Recent reports that MMP-1 binds to ␣2 ␤1 integrins on the cell membrane of human keratinocytes and monocytes, 28,29 causing regulation of migratory activities, highlights the biological importance of this cell-associated molecule in inflammatory and proliferative cell processes.…”

Structural Analysis of the α2 Integrin I Domain/Procollagenase-1 (Matrix Metalloproteinase-1) Interaction

“…In addition, recombinant ␣ 2 integrin I domain specifically binds all known ligands of the ␣ 2 ␤ 1 integrin, including collagens, laminin, the C-terminal propeptide of type I collagen, and echovirus 1 and 8 (20,22). In the accompanying paper (23), we demonstrated that, in addition to inducing expression of MMP-1, the ␣ 2 ␤ 1 integrin also directly binds MMP-1. In this paper, we show that MMP-1 binds to the I domain of the ␣ 2 integrin subunit, and we define the structural basis of the interaction.…”

“…Cell lysates were prepared as described (23). The ␣ 1 integrin subunit was immunoprecipitated using a monoclonal antibody from Chemicon International Inc. (Temecula, CA).…”