Granzyme H (GZMH)

Granzyme H is a chymotrypsin-like serine protease encoded by the GZMH gene and predominantly expressed in the cytotoxic granules of human natural killer (NK) cells and cytotoxic T lymphocytes. It contributes critically to innate immune defense by inducing programmed cell death in target cells, including tumor and virus-infected cells, through both caspase-dependent and independent pathways. Granzyme H also has direct antiviral activity by cleaving viral proteins and can complement the activity of granzyme B by counteracting viral inhibitors. Its proteolytic activity depends on structural motifs defining substrate specificity, notably an RKR motif. Granzyme H is being explored as a functional molecule in tumor immunity and viral infections, and is a target for experimental inhibitors, but lacks well-validated therapeutics approved for direct modulation.

Other names

CGL2CTSGL2CSP-CCGL-2CCP-XCTLA1Cathepsin G-like 2Cytotoxic T-lymphocyte proteinaseCytotoxic serine protease Cprotein h-CCPXcytotoxic T-lymphocyte-associated serine esterase 1cytotoxin serine protease-C

Proteolytic cleavage of target proteins leading to apoptosis (including Bid and ICAD/DFF45). Direct anti-viral action by degradation of viral proteins.