Transglutaminase 2 inhibits apoptosis induced by calcium- overload through down-regulation of Bax.

An abrupt increase of intracellular Ca(2+) is observed in cells under hypoxic or oxidatively stressed conditions. The dysregulated increase of cytosolic Ca(2+) triggers apoptotic cell death through mitochondrial swelling and activation of Ca(2+)-dependent enzymes. Transglutaminase 2 (TG2) is a Ca(2+)-dependent enzyme that catalyzes transamidation reaction producing cross-linked and polyaminated proteins.