Jorgensen A O, Shen A C, Campbell K P, MacLennan D H
J Cell Biol. 1983 Nov;97(5 Pt 1):1573-81. doi: 10.1083/jcb.97.5.1573.
The ultrastructural localization of calsequestrin in rat skeletal muscle (gracilis) was determined by indirect immunoferritin labeling of ultrathin frozen sections. Calsequestrin was found in the lumen of transversely and longitudinally oriented terminal cisternae but was absent from most of the longitudinal sarcotubules and the fenestrated sarcoplasmic reticulum. Calsequestrin was occasionally observed in vesicular structures found in the central region of the I band. Since calsequestrin is believed to provide the major site of Ca2+ sequestration in the sarcoplasmic reticulum, the present results support the view that Ca2+, transported to the lumen of the sarcoplasmic reticulum, is preferentially sequestered in the terminal cisternae, but they also suggest that additional Ca2+ sequestration may occur near the center of the I band.
通过对超薄冰冻切片进行间接免疫铁蛋白标记，确定了大鼠骨骼肌（股薄肌）中肌钙蛋白的超微结构定位。肌钙蛋白存在于横向和纵向排列的终池管腔中，但在大多数纵向肌小管和有窗孔的肌浆网中不存在。在I带中央区域的泡状结构中偶尔观察到肌钙蛋白。由于肌钙蛋白被认为是肌浆网中Ca2+储存的主要部位，目前的结果支持这样一种观点，即转运到肌浆网管腔中的Ca2+优先储存在终池中，但也表明在I带中心附近可能会发生额外的Ca2+储存。
