title: Molecular and cell biology of the sarcoglycan complex.
abstract: The original sarcoglycan (SG) complex has four subunits and comprises a subcomplex of the dystrophin-dystrophin-associated protein complex. Each SG gene has been shown to be responsible for limb-girdle muscular dystrophy, called sarcoglycanopathy (SGP). In this review, we detail the characteristics of the SG subunits, and the mechanism of the formation of the SG complex and various molecules associated with this complex. We discuss the molecular mechanisms of SGP based on studies mostly using SGP animal models. In addition, we describe other SG molecules, epsilon- and zeta-SGs, with special reference to their expression and roles in vascular smooth muscle, which are currently in dispute. We further consider the maternally imprinted nature of the epsilon-SG gene. Finally, we stress that the SG complex cannot work by itself and works in a larger complex system, called the transverse fixation system, which forms an array of molecules responsible for various muscular dystrophies.
authors.affiliation: National Institute of Neuroscience, National Center of Neurology and Psychiatry, Ogawahigashi-cho, Kodaira, Tokyo, Japan. ozawa@ncnp.go.jp
authors.forename: Eijiro
authors.initials: E
authors.lastname: Ozawa
authors.forename: Yuji
authors.initials: Y
authors.lastname: Mizuno
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Hagiwara
authors.forename: Toshikuni
authors.initials: T
authors.lastname: Sasaoka
authors.forename: Mikiharu
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D004421:Dystonia / Q000235:genetics; D005786:Gene Expression Regulation; D018392:Genomic Imprinting; D009130:Muscle, Smooth / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D049288:Muscular Dystrophies, Limb-Girdle / Q000235:genetics*; D009206:Myocardium / Q000378:metabolism; D009207:Myoclonus / Q000235:genetics; D049031:Sarcoglycans / Q000235:genetics / Q000378:metabolism*; D013577:Syndrome
chemical_list: D049031:Sarcoglycans