Restoration of junctional tetrads in dysgenic myotubes by dihydropyridine receptor cDNA.
Restoration of junctional tetrads in dysgenic myotubes by dihydropyridine receptor cDNA.
复制标题
通过二氢吡啶受体 cDNA 恢复发育不良肌管中的连接四分体。
DOI：
10.1016/s0006-3495(94)80539-9
复制
发表时间：
1994
影响因子：
3.4
通讯作者：
Franzini-Armstrong,C
中科院分区：
文献类型：
--
作者：
Takekura,H;Bennett,L;Tanabe,T;Beam,KG;Franzini-Armstrong,C
通过用编码兔骨骼肌二氢吡啶受体的表达质粒转染原代培养的发育不良肌管细胞，恢复兴奋-收缩偶联。将含有正常、发育不良和转染的肌管的培养皿固定、冷冻断裂并复制用于电子显微镜检查。正常肌管的表面膜中的许多小结构域包含四个一组的膜内颗粒的有序阵列（四分体）。在阵列中的四分体的处置是一致的交替定位的四分体相对于下面的脚的肌浆网。基因异常的肌管没有四分体阵列。一些成功转染培养物的肌管具有间距等于正常肌管中发现的间距的四分体阵列。因此，二氢吡啶受体似乎是必要的四分体的形成和他们的协会与肌浆网脚。这一结果与每个四分体由四个二氢吡啶受体组成的假设一致。
Excitation-contraction coupling was restored in primary cultures of dysgenic myotubes by transfecting the cells with an expression plasmid encoding the rabbit skeletal muscle dihydropyridine receptor. Dishes containing normal, dysgenic, and transfected myotubes were fixed, freeze-fractured, and replicated for electron microscopy. Numerous small domains in the surface membrane of normal myotubes contain ordered arrays of intramembrane particles in groups of four (tetrads). The disposition of tetrads in the arrays is consistent with alternate positioning of tetrads relative to the underlying feet of the sarcoplasmic reticulum. Dysgenic myotubes have no arrays of tetrads. Some myotubes from successfully transfected cultures have arrays of tetrads with spacings equal to those found in normal myotubes. Thus the dihydropyridine receptor appears to be needed for the formation of tetrads and their association with the sarcoplasmic reticulum feet. This result is consistent with the hypothesis that each tetrad is composed of four dihydropyridine receptors.