Structure and physiological function of calpains

• Published in: Biochemical journal Vol. 328 ( Pt 3); no. 3; pp. 721 - 732
• Main Authors: Sorimachi, H, Ishiura, S, Suzuki, K
• Format: Journal Article
• Language: English
• Published: England 15.12.1997
• Subjects: Amino Acid Sequence; Animals; Apoptosis; Brain - physiology; Calcium - metabolism; Calcium-Binding Proteins - chemistry; Calpain - antagonists & inhibitors; Calpain - chemistry; Calpain - physiology; Cysteine Endopeptidases - chemistry; Cysteine Endopeptidases - metabolism; Cysteine Proteinase Inhibitors - chemistry; Cysteine Proteinase Inhibitors - pharmacology; Humans; Molecular Sequence Data; Sex Determination Processes
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/bj3280721

For a long time now, two ubiquitously expressed mammalian calpain isoenzymes have been used to explore the structure and function of calpain. Although these two calpains, mu- and m-calpains, still attract intensive interest because of their unique characteristics, various distinct homologues to the protease domain of mu- and m-calpains have been identified in a variety of organisms. Some of these 'novel' calpain homologues are involved in important biological functions. For example, p94 (also called calpain 3), a mammalian calpain homologue predominantly expressed in skeletal muscle, is genetically proved to be responsible for limb-girdle muscular dystrophy type 2A. Tra-3, a calpain homologue in nematodes, is involved in the sex determination cascade during early development. PalB, a key gene product involved in the alkaline adaptation of Aspergillus nidulans, is the first example of a calpain homologue present in fungi. These findings indicate various important functional roles for intracellular proteases belonging to the calpain superfamily.