title: Human cardiac and skeletal muscle spectrins: differential expression and localization.
abstract: We describe multiple human cardiac and skeletal muscle spectrin isoforms. Cardiac muscle expresses five erythroid alpha,beta spectrin-reactive isoforms with estimated MR's of 280, 274, 270, 255, and 246 kD, respectively. At least one nonerythroid alpha-spectrin of MR 284 kD is expressed in heart. While skeletal muscle shares the 280, 270, and 246 kD erythroid spectrins, it expresses an immunologically distinct 284 kD nonerythroid alpha-spectrin isoform. The 255 kD erythroid beta-spectrin isoform is specific for cardiac tissue. By immunocytochemistry, both erythroid beta- and nonerythroid alpha-spectrins are localized to costameres, the plasma membrane, and the neuromuscular junctional region.
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, Texas 77030.
authors.forename: T
authors.initials: T
authors.lastname: Vybiral
authors.forename: J C
authors.initials: JC
authors.lastname: Winkelmann
authors.forename: R
authors.initials: R
authors.lastname: Roberts
authors.forename: E
authors.initials: E
authors.lastname: Joe
authors.forename: D L
authors.initials: DL
authors.lastname: Casey
authors.forename: J K
authors.initials: JK
authors.lastname: Williams
authors.forename: H F
authors.initials: HF
authors.lastname: Epstein
mesh_terms: D000328:Adult; D000906:Antibodies; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007150:Immunohistochemistry; D009132:Muscles / Q000737:chemistry*; D009206:Myocardium / Q000737:chemistry*; D009469:Neuromuscular Junction / Q000737:chemistry; D013049:Spectrin / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D000906:Antibodies; D013049:Spectrin