Membrane-type matrix metalloproteinase-1 (MT1-MMP) is a processing enzyme for human laminin gamma 2 chain

J Biol Chem. 2005 Jan 7;280(1):88-93. doi: 10.1074/jbc.M411824200. Epub 2004 Nov 3.

Abstract

Processing of the laminin-5 (Ln-5) gamma 2 chain by membrane-type-1 matrix metalloproteinases (MT1-MMP) promotes migration and invasion of epithelial and tumor cells. We previously demonstrated that MT1-MMP cleaves the rat gamma 2 chain at two sites, producing two major C-terminal fragments of 100 (gamma 2') and 80 (gamma 2 x) kDa and releasing a 30-kDa fragment containing epidermal growth factor (EGF)-like motifs (domain III (DIII) fragment). The DIII fragment bound the EGF receptor (EGF-R) and stimulated cell scattering and migration. However, it is not yet clear whether human Ln-5 is processed in a similar fashion to rat Ln-5 because one of the two MT1-MMP cleavage sites present in rat gamma 2 is not found in human gamma 2. To identify the exact cleavage site for MT1-MMP in human Ln-5, we purified both the whole molecule as well as a monomeric form of human gamma 2 that is frequently expressed by malignant tumor cells. Like rat Ln-5, both the monomer of gamma 2, as well as the gamma 2 derived from intact Ln-5, were cleaved by MT1-MMP in vitro, generating C-terminal gamma 2' (100 kDa) and gamma 2 x (85 kDa) fragments and releasing DIII fragments (25 and 27k Da). In addition to the conserved first cleavage site used to generate gamma 2', two adjacent cleavage sites (Gly(559)-Asp(560) and Gly(579)-Ser(580)) were found that could generate the gamma 2 x and DIII fragments. Two of the three EGF-like motifs present in the rat DIII fragment are present in the 27-kDa human fragment, and like the rat DIII, this fragment can promote breast carcinoma cell migration by engaging the EGF-R. These results suggest that MT1-MMP processing of Ln-5 in human tumors may stimulate the EGF-R, resulting in increased tumor cell scattering and migration that could possibly increase their metastatic potential.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Cell Line, Tumor
  • Cell Movement
  • ErbB Receptors / metabolism
  • Humans
  • Laminin / genetics
  • Laminin / metabolism*
  • Matrix Metalloproteinases, Membrane-Associated
  • Metalloendopeptidases / genetics
  • Metalloendopeptidases / metabolism*
  • Neoplasm Invasiveness
  • Rats
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Substrate Specificity

Substances

  • LAMC2 protein, human
  • Laminin
  • Recombinant Proteins
  • ErbB Receptors
  • Matrix Metalloproteinases, Membrane-Associated
  • Metalloendopeptidases