Holda J R, Blatter L A
Department of Physiology, Loyola University Chicago, Maywood, IL 60153, USA.
FEBS Lett. 1997 Feb 17;403(2):191-6. doi: 10.1016/s0014-5793(97)00051-3.
The role of an intact cytoskeleton for store-operated ('capacitative') Ca2+ influx was investigated in single cultured vascular endothelial cells. Capacitative Ca2+ entry was measured as changes of cytoplasmic Ca2+ concentration ([Ca2+]i) induced by depletion of Ca2+ stores with thapsigargin. In cells pretreated with cytochalasin D, an agent that disrupts the microfilament network of the cytoskeleton, as confirmed with FITC-phalloidin staining, capacitative Ca2+ entry was inhibited. Cytochalasin D did not affect basal [Ca2+]i nor ATP-induced increases of [Ca2+]i, indicating that release of Ca2+ from intracellular stores through the inositol-phosphate pathway was intact. These results suggest that microfilaments are an integral part of the mechanism for capacitative Ca2+ entry. The necessity for an intact cytoskeleton favors a conformational coupling model for store-operated Ca2+ influx.
在单个培养的血管内皮细胞中，研究了完整细胞骨架在储存操纵性（“容量性”）Ca2+内流中的作用。通过用毒胡萝卜素耗尽Ca2+储存所诱导的细胞质Ca2+浓度（[Ca2+]i）变化来测量容量性Ca2+内流。用细胞松弛素D预处理细胞，细胞松弛素D是一种破坏细胞骨架微丝网络的试剂，经异硫氰酸荧光素鬼笔环肽染色证实，容量性Ca2+内流受到抑制。细胞松弛素D不影响基础[Ca2+]i，也不影响ATP诱导的[Ca2+]i增加，这表明通过肌醇磷酸途径从细胞内储存中释放Ca2+是完整的。这些结果表明，微丝是容量性Ca2+内流机制的一个组成部分。完整细胞骨架的必要性支持了储存操纵性Ca2+内流的构象偶联模型。
