Membrane-type I metalloproteinase (MT1-MMP): A key modifier of extracellular matrix microenvironment.

Extracellular matrix (ECM) is a major component of the cellular microenvironment. It holds cells, directly sends signals to the cells, pools growth factors and cytokines, and guides cell migration and differentiation. A type I transmembrane proteinase, membrane-type I matrix metalloproteinase (MT1-MMP/MMP14), degrades ECM at the cell surface and cleaves cell surface receptors, thereby modifying cellular behavior. It is a major promoter of cell invasion and tissue destruction in diseases, such as cancer and arthritis, and is a crucial enzyme that maintains fibrillar collagen homeostasis in stromal tissue. This review discusses the current understanding of the function and regulation of this important cell surface proteinase in health and disease.