Human cardiac and skeletal muscle spectrins: differential expression and localization.
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.
Vybiral
T
T
Department of Neurology, Baylor College of Medicine, Houston, Texas 77030.
Winkelmann
J C
JC
Roberts
R
R
Joe
E
E
Casey
D L
DL
Williams
J K
JK
Epstein
H F
HF
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
D000906:Antibodies; D013049:Spectrin