title: Calpain chronicle--an enzyme family under multidisciplinary characterization.
abstract: Calpain is an intracellular Ca2+-dependent cysteine protease (EC 3.4.22.17; Clan CA, family C02) discovered in 1964. It was also called CANP (Ca2+-activated neutral protease) as well as CASF, CDP, KAF, etc. until 1990. Calpains are found in almost all eukaryotes and a few bacteria, but not in archaebacteria. Calpains have a limited proteolytic activity, and function to transform or modulate their substrates' structures and activities; they are therefore called, "modulator proteases." In the human genome, 15 genes--CAPN1, CAPN2, etc.--encode a calpain-like protease domain. Their products are calpain homologs with divergent structures and various combinations of functional domains, including Ca2+-binding and microtubule-interaction domains. Genetic studies have linked calpain deficiencies to a variety of defects in many different organisms, including lethality, muscular dystrophies, gastropathy, and diabetes. This review of the study of calpains focuses especially on recent findings about their structure-function relationships. These discoveries have been greatly aided by the development of 3D structural studies and genetic models.
authors.affiliation: Calpain Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan. sorimachi-hr@igakuken.or.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sorimachi
authors.forename: Shoji
authors.initials: S
authors.lastname: Hata
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Ono
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002154:Calpain / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism; D004194:Disease; D004789:Enzyme Activation; D006801:Humans; D008969:Molecular Sequence Data; D009928:Organ Specificity; D017434:Protein Structure, Tertiary
chemical_list: D002154:Calpain