MT1-MMP (green) is inactive when associated with β1 integrin (red, left) between static cells, but active when associated with αvβ3 integrin (red, right) in migrating cells.
Many different proteins, such as collagen (COL), fibronectin (FN), and gelatin (GEL), make up the basement membranes and connective tissues of ECM-rich tissues. Their degradation by membrane-type matrix metalloprotease 1 (MT1-MMP) is required for cell migration. But it now appears that ECM proteins are not passive victims in this process—they influence the location and activity of the protease by recruiting the help of cell adhesion receptors.
Using MT1-MMP fused to GFP in endothelial cells, Gálvez et al. noted that the protease had an unusual association with β1 integrin at cell–cell contact sites on β1 integrin–dependent substrates...
