Coexistence of two calsequestrin isoforms in rabbit slow‐twitch skeletal muscle fibers

摘要

>The cardiac and skeletal muscle isoforms of calsequestrin (CS), the low affinity, high capacity Ca2+ binding protein localized in the lumen of sarcoplasmic reticulum, are the products of two different genes (Fliegel, L., Leberer, E., Green, N.M. and MacLennan, D.H. (1982) FEBS Lett. 242, 297–300), and can be both purified from slow-twitch skeletal muscle of the rabbit (Damiani, E., Volpe, P. and Margreth, A. (1990) J. Muscle Res. Cell Motil. 11, 522–530). Here we show that both CS isoforms coexist in slow-twitch muscle fibers as indicated by indirect immunofluorescent staining of cryosections with affinity-purified antibodies specific for each CS isoform.