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Updated: Jul 15, 2026

Organotypic Collagen I Assay: A Malleable Platform to Assess Cell Behaviour in a 3-Dimensional Context
Published on: October 13, 2011
Pro-collagenase-1 (matrix metalloproteinase-1) binds the alpha(2)beta(1) integrin upon release from keratinocytes
J A Dumin1, S K Dickeson, T P Stricker
1Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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 alpha(2)beta(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 alpha(2)beta(1) contacts in migrating keratinocytes. Furthermore, pro-MMP-1 co-immunoprecipitated with alpha(2)beta(1) from keratinocytes, and alpha(2)beta(1) co-immunoprecipitated with pro-MMP-1. No other MMPs bound alpha(2)beta(1), and no other integrins interacted with MMP-1. Pro-MMP-1 also provided a substrate for alpha(2)beta(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 alpha(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 alpha(2)beta(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.
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