Golgi complex reorganization during muscle differentiation: Visualization in living cells and mechanism
Golgi complex reorganization during muscle differentiation: Visualization in living cells and mechanism
复制标题
DOI：
10.1091/mbc.12.4.795
复制
发表时间：
2001-04-01
影响因子：
3.3
通讯作者：
Ralston, E
中科院分区：
文献类型：
--
作者：
Lu, ZM;Joseph, D;Ralston, E
在骨骼肌分化过程中，高尔基复合体（GC）经历了戏剧性的重组。我们现在已经看到了小鼠肌细胞系C2的活成肌细胞的分化和融合，永久表达甘露聚糖酶-绿色荧光蛋白（GFP）构建体。这些实验表明，GC的重组是渐进的（1-2小时），并在细胞开始融合之前完成。荧光恢复后的光漂白（FRAP），免疫荧光，免疫金电子显微镜表明，GC被分割成元件定位附近的内质网（ER）出口网站。FRAP分析和内源性GC蛋白的ER迁移磷脂酶A2抑制剂表明，高尔基体-ER循环的居民GC蛋白发生在成肌细胞和肌管。所有的结果支持的模型，其中GC重组肌肉反映了高尔基体-ER循环的变化。其机制类似于微管破坏药物导致所有哺乳动物细胞中GC分散的机制。我们建议，触发器的分散结果，在肌肉中，从微管成核和ER出口网站本地化，这将ER出口网站附近的微管负端的组合变化。因此，GC组织的变化最初表现为肌肉细胞特有的，但事实上使用所有哺乳动物细胞共有的途径。
During skeletal muscle differentiation, the Golgi complex (GC) undergoes a dramatic reorganization. We have now visualized the differentiation and fusion of living myoblasts of the mouse muscle cell line C2, permanently expressing a mannosidase-green fluorescent protein (GFP) construct. These experiments reveal that the reorganization of the GC is progressive (1-2 h) and is completed before the cells start fusing. Fluorescence recovery after photobleaching (FRAP), immunofluorescence, and immunogold electron microscopy demonstrate that the GC is fragmented into elements localized near the endoplasmic reticulum (ER) exit sites. FRAP analysis and the ER relocation of endogenous GC proteins by phospholipase A2 inhibitors demonstrate that Golgi-ER cycling of resident GC proteins takes place in both myoblasts and myotubes. All results support a model in which the GC reorganization in muscle reflects changes in the Golgi-ER cycling. The mechanism is similar to that leading to the dispersal of the GC caused, in all mammalian cells, by microtubule-disrupting drugs. We propose that the trigger for the dispersal results, in muscle, from combined changes in microtubule nucleation and ER exit site localization, which place the ER exit sites near microtubule minus ends. Thus, changes in GC organization that initially appear specific to muscle cells, iri fact use pathways common to all mammalian cells.