Granzyme M (GZMM)

Granzyme M is a cytotoxic serine protease—specifically, a member of the granzyme family—predominantly expressed and stored in the cytoplasmic granules of human natural killer (NK) cells and certain cytotoxic T lymphocyte subsets[2][4]. Unlike granzyme A and B, Granzyme M triggers cell death through a unique pathway that is independent of classic caspase activation, does not induce major DNA fragmentation, and is not inhibited by anti-apoptotic Bcl-2 family proteins[3][5]. Its principal function is to mediate rapid, perforin-dependent death of tumor, virus-infected, or otherwise aberrant target cells as part of the host innate and adaptive immune response[3][4][5][7]. Granzyme M displays a preference for cleaving after methionine or leucine residues, and its substrates include pro-survival proteins and viral components, indicating functional roles in regulating cell death and antiviral defense[4][5][7]. It is an established biomarker for certain NK/T-cell lymphomas and is being investigated both as a functional immune marker and potential therapeutic target in cancer and infection contexts[8].

Other names

Met-1 serine proteaseMET1LMET1Met-aseNatural killer cell granular proteaselymphocyte met-ase 1HU-Met-1GRAM_HUMANgranzyme M (lymphocyte met-ase 1)

Protease inhibition (targeting GZMM with specific protease inhibitors blocks its cytolytic and apoptotic activities)