MT4MMP

MT4-MMP, also known as MT4-MMP or MMP-17, is a member of the matrix metalloproteinase (MMP) family, zinc-dependent endopeptidases that remodel the extracellular matrix (ECM). The MT4-MMP protein is encoded by the MMP17 gene in humans. It is a membrane-type MMP that is primarily GPI-anchored to the cell surface, distinguishing it from transmembrane MT-MMPs; some forms can be shed by phospholipases to yield a soluble protease. The enzyme is synthesized as an inactive zymogen with a propeptide that keeps it latent until proteolytic removal.

Substrate specificity for MT4-MMP includes components of the ECM; it can contribute to pericellular ECM remodeling and may participate in processing other proteins at the cell surface. In practice, MT4-MMP activity is regulated by TIMPs (tissue inhibitors of metalloproteinases) and by cellular localization. Expression of MT4-MMP has been observed in multiple tissues and cell types, and its levels can be modulated in inflammatory conditions and cancer. Functional studies suggest roles in development, angiogenesis, wound healing, and potentially tumor invasion and metastasis, though the exact physiological and pathological contributions are context dependent.

Because the MT4-MMP family members show diverse regulation and substrate repertoires, ongoing research continues to define its precise substrates and regulatory mechanisms. See also matrix metalloproteinases, MT1-MMP, TIMPs, and MMP-2 activation pathways.