The subcellular distribution of dystrophin in mouse skeletal, cardiac, and smooth muscle.
The subcellular distribution of dystrophin in mouse skeletal, cardiac, and smooth muscle.
复制标题
抗肌萎缩蛋白在小鼠骨骼、心脏和平滑肌中的亚细胞分布。
DOI：
10.1083/jcb.115.2.411
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发表时间：
1991-10
期刊：
影响因子：
--
通讯作者：
Watkins SC
中科院分区：
文献类型：
--
作者：
Byers TJ;Kunkel LM;Watkins SC
我们使用一种高度特异性和敏感性的抗体，以进一步表征肌营养不良蛋白在骨骼肌，心脏和平滑肌中的分布。在骨骼肌中，除了细胞表面之外，没有证据表明存在定位，并且在坐骨神经中未检测到427-kD肌营养不良蛋白标记。肌腱接头和神经肌肉接头处出现肌营养不良蛋白浓度升高，后者的标记更强烈，特别是在突触褶皱的谷中。在心肌中，肌营养不良蛋白的分布仅限于表面质膜，但明显不存在于覆盖闰盘的粘附连接的膜。在平滑肌中，质膜标记比心肌或骨骼肌中的丰富得多，并且在膜囊泡下方的膜区域中发现。在心肌中，平滑肌肌营养不良蛋白似乎被排除在膜上的密度，标志着粘附连接。肌营养不良蛋白在骨骼肌和心肌的蛋白质印迹上显示为双峰，并且在平滑肌中显示为较低丰度的单一条带，其在分子量上最接近于横纹肌双峰的上部条带。在横纹肌中的双联体的较低带似乎缺乏羧基末端的一部分，并且可能代表肌营养不良蛋白同种型。同种型差异和肌营养不良蛋白在不同专门的膜表面上的存在意味着肌营养不良蛋白蛋白的多种功能作用。
We use a highly specific and sensitive antibody to further characterize the distribution of dystrophin in skeletal, cardiac, and smooth muscle. No evidence for localization other than at the cell surface is apparent in skeletal muscle and no 427-kD dystrophin labeling was detected in sciatic nerve. An elevated concentration of dystrophin appears at the myotendinous junction and the neuromuscular junction, labeling in the latter being more intense specifically in the troughs of the synaptic folds. In cardiac muscle the distribution of dystrophin is limited to the surface plasma membrane but is notably absent from the membrane that overlays adherens junctions of the intercalated disks. In smooth muscle, the plasma membrane labeling is considerably less abundant than in cardiac or skeletal muscle and is found in areas of membrane underlain by membranous vesicles. As in cardiac muscle, smooth muscle dystrophin seems to be excluded from membrane above densities that mark adherens junctions. Dystrophin appears as a doublet on Western blots of skeletal and cardiac muscle, and as a single band of lower abundance in smooth muscle that corresponds most closely in molecular weight to the upper band of the striated muscle doublet. The lower band of the doublet in striated muscle appears to lack a portion of the carboxyl terminus and may represent a dystrophin isoform. Isoform differences and the presence of dystrophin on different specialized membrane surfaces imply multiple functional roles for the dystrophin protein.