A protease that is stored in the lysosomal-granules of natural killer cells and cytotoxic lymphocytes that cleaved intracellular substrates to trigger apoptosis pathway.
Granzyme A is present in cytotoxic T lymphocytes granules that initiates caspase independent cell death pathway to ensure the target cell dies. It is programmed to activate cell death that commence in mitochondrion that generates reactive oxygen to ultimately activate single-strand DNA damage. It also targets other significant nuclear protein for degradation such as lamins, histones and some DNA damage repair protein.
Granzyme A induces caspase independent apoptosis and plays a vital role in the immune defense against intracellular bacteria, viruses and tumors. It also shows to aid in extracellular destruction of tissue and vascular veracity that involved in inflammatory and age-related diseases, thus act as the most important protein rivet in immune function and surveillance. It displays proinflammatory activity that activates IL-1, TNF- α and IL-6.
Granzyme A has a genomic organization of two mRNAs encoded with different peptides. It is the most numerous serine proteases in CD8 and Natural killer cell granules. It cleaves Ku70, a double strand break repair protein in which Granzyme A disrupts Ku70 complex to bind in DNA and facilitates cell death wherein expression of Ku70 decrease DNA damage and minimize cell death.
Gene name: GZMA
Protein name: Granzyme A
• CTL tryptase
• Cytotoxic T-lymphocyte proteinase 1
• Hanukkah factor