Vohra M S, Komiyama M, Hayakawa K, Obinata T, Shimada Y
Department of Anatomy and Cell Biology, School of Medicine, Chiba University, Chiba 260-8670, Japan.
Cell Tissue Res. 1998 Oct;294(1):137-43. doi: 10.1007/s004410051163.
The subcellular localization of dystrophin and vinculin was investigated in cardiac muscle fibers and fibers of the conduction system of the chicken ventricle by immunofluorescence confocal microscopy. In ventricular cardiac muscle fibers, strong staining with antibody against dystrophin appeared as regularly arranged transverse striations at the sarcolemmal surface, and faint but uniform staining was seen in narrow strips between these striations. In fibers of the ventricular conduction system, the sarcolemma was stained uniformly with this antibody, but strong staining was found as regular striations in many areas and as scattered patches in other areas of the sarcolemma. These intensely stained striations and scattered patches of dystrophin were colocalized with those of vinculin. Because dystrophin striations were located at the level of Z bands of the underlying myofibrils, they were regarded as the concentration of this protein at costameres together with vinculin. In fibers of the conduction system, myofibrils were close to the sarcolemma where dystrophin and vinculin assumed a striated pattern, at some distance from the cell membrane where these proteins exhibited a patchy distribution, and distant from the sarcolemma where dystrophin was uniformly distributed. These data suggest that the distribution patterns of dystrophin reflect the degree of association between the sarcolemma and underlying myofibrils.
通过免疫荧光共聚焦显微镜研究了肌营养不良蛋白和纽蛋白在鸡心室心肌纤维和传导系统纤维中的亚细胞定位。在心室心肌纤维中，抗肌营养不良蛋白抗体的强染色表现为肌膜表面规则排列的横向条纹，在这些条纹之间的窄条中可见微弱但均匀的染色。在心室传导系统的纤维中，该抗体使肌膜均匀染色，但在肌膜的许多区域发现强染色呈规则条纹，在其他区域呈散在斑块状。这些肌营养不良蛋白的强染色条纹和散在斑块与纽蛋白的条纹和斑块共定位。由于肌营养不良蛋白条纹位于下方肌原纤维Z带水平，它们被认为是该蛋白与纽蛋白在肌小节处的聚集。在传导系统的纤维中，肌原纤维靠近肌膜处，肌营养不良蛋白和纽蛋白呈条纹状分布；在距细胞膜一定距离处，这些蛋白呈斑块状分布；在远离肌膜处，肌营养不良蛋白呈均匀分布。这些数据表明，肌营养不良蛋白的分布模式反映了肌膜与下方肌原纤维之间的关联程度。
