Calpain-1 catalytic subunit (CAPN1, also known as mu-calpain) belongs to the calpain family, which consists of a group of Ca2+ dependent cysteine proteases that regulate functions of substrates by proteolysis [, ]. The most abundant members of the calpain familiy are CAPN1 and CAPN2. They form heterodimers, which are regulated by a small regulatory subunit (28kDa) encoded by the gene Capn4 []. Calpain-1 plays a role in regulating IgE-mediated mast cell activation []. Calpain-1 is also involved in mammary gland remodelling [].
Calpain-2 (CAPN2, also known as m-calpain) belongs to the calpain family, which consists of a group of Ca2+ dependent cysteine proteases that regulate functions of substrates by proteolysis [, ]. The most abundant members of the calpain familiy are CAPN1 and CAPN2. They form heterodimers, which are regulated by a small regulatory subunit (28kDa) encoded by the gene Capn4 []. CAPN2 is required for proteolysis of cytoskeletal and focal adhesion proteins, such as FAK, paxillin, spectrin, and talin []. The cleavage of the cytoskeletal protein talin-1 (TLN1) by CAPN2 is critical for the disassembly of focal adhesions [].
