Association of microinjected myosin and its subfragments with myofibrils in living muscle cells.
Association of microinjected myosin and its subfragments with myofibrils in living muscle cells.
复制标题
显微注射的肌球蛋白及其亚片段与活体肌肉细胞中肌原纤维的关联。
DOI：
10.1083/jcb.107.6.2213
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Wang,Y
中科院分区：
文献类型：
--
作者：
Johnson,CS;McKenna,NM;Wang,Y
Purified skeletal muscle myosin was labeled with iodoacetamidofluorescein and microinjected into cultured chick myotubes. The fluorescent myosin analogue became incorporated within 10-15 min after injection, into either periodic (mean periodicity = 2.23 +/- 0.02 micron) bands or apparently continuous fibrillar structures. Comparison of rhodamine-labeled alpha-actinin with coinjected fluorescein-labeled myosin suggested that myosin fluorescence was localized at the A-bands of myofibrils. In addition, close examination of the fluorescent myosin bands indicated that they were composed of two fluorescent bars separated by a nonfluorescent line that corresponded to the H-zone. Once incorporated, the myosin underwent a relatively slow exchange along myofibrils as indicated by fluorescence recovery after photobleaching. Glycerinated myofibrils were able to bind fluorescent myosin in a similar pattern in the presence or absence of MgATP, indicating that actin-myosin interactions had little effect on this process. Fluorescent heavy meromyosin did not incorporate into myofibrillar structures after injection. Light meromyosin, however, associated with A-bands as did whole myosin. These results suggest that microinjected myosin, even with its relatively low solubility under the cytoplasmic ionic condition, is capable of association with physiological structures in living muscle cells. Additionally, the light meromyosin portion of the molecule appears to be mainly responsible for the incorporation.
