Franzini-Armstrong C, Kenney L J, Varriano-Marston E
J Cell Biol. 1987 Jul;105(1):49-56. doi: 10.1083/jcb.105.1.49.
We have examined the structure of calsequestrin in three-dimensional images from deep-etched rotary-replicated freeze fractures of skeletal muscle fibers. We selected a fast-acting muscle because the sarcoplasmic reticulum has an orderly disposition and is rich in internal membranes. Calsequestrin forms a network in the center of the terminal cisternae and is anchored to the sarcoplasmic reticulum membrane, with preference for the junctional portion. The anchorage is responsible for maintaining calsequestrin in the region of the sarcoplasmic reticulum close to the calcium-release channels, and it corroborates the finding that calsequestrin and the spanning protein of the junctional feet may interact with each other in the junctional membrane. Anchoring filaments may be composed of a protein other than calsequestrin.
我们通过骨骼肌纤维深蚀刻旋转复制冷冻断裂的三维图像研究了肌集钙蛋白的结构。我们选择了一种快肌，因为肌浆网具有有序的排列且富含内膜。肌集钙蛋白在终末池中央形成网络，并锚定在肌浆网膜上，尤其偏好连接部分。这种锚定作用负责将肌集钙蛋白维持在靠近钙释放通道的肌浆网区域，并且证实了肌集钙蛋白与连接足的跨膜蛋白可能在连接膜中相互作用这一发现。锚定丝可能由除肌集钙蛋白之外的一种蛋白质组成。
