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]
Forensic Context
A study in humans demonstrated that the CAPN1 mRNA was upregulated in both acute emergency department and outpatient concussion clinic patient groups with mild traumatic brain injury compared to controls, as indicated by a fold change greater than two [Cheng et al. DOI:10.1002/jcp.28139].