Background:
The calpains,calcium-activated neutral proteases,are nonlysosomal,intracellular cysteine proteases. The mammalian calpains include ubiquitous,stomach-specific,and muscle-specific proteins. The ubiquitous enzymes consist of heterodimers with distinct large,catalytic subunits associated with a common small,regulatory subunit. This gene encodes the large subunit of the ubiquitous enzyme,calpain 1. Several transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq,Nov 2010]