FIBRONECTIN EXPRESSION DURING MYOGENESIS
FIBRONECTIN EXPRESSION DURING MYOGENESIS
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DOI：
10.1083/jcb.96.2.474
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发表时间：
1983-01-01
影响因子：
7.8
通讯作者：
FAMBROUGH, DM
中科院分区：
文献类型：
--
作者：
GARDNER, JM;FAMBROUGH, DM
描述了鸡肌肉分化过程中纤连蛋白的生物合成和定位。使用了两种单克隆抗体，一种选择性杀死单核细胞，另一种对禽类纤连蛋白具有特异性。这些抗体可以精确分析明确的成肌细胞或肌管培养物中的纤连蛋白表达，并避免外源纤连蛋白的并发症以及成纤维细胞或未融合的成肌细胞的污染。纤连蛋白合成作为总蛋白质合成的一部分，在成肌细胞融合前后保持恒定在0.3-0.4%，这表明当肌管合成和积累肌原纤维蛋白时，纤连蛋白合成的绝对速率可能有所增加。纤连蛋白的排列模式在肌生成过程中确实发生了变化。在肌管培养物中，脉冲标记的纤连蛋白在细胞表面出现，并在 2 至 3 小时的滞后期后开始分泌到培养基中，而在成纤维细胞培养物中观察到的滞后期为 30 分钟。因此，多肽生物合成和新蛋白质外化之间的这种滞后是每种细胞类型的特征，而不是蛋白质的特征。肌原细胞的所有主要分泌蛋白，包括纤连蛋白和胶原成分，都具有 2 至 3 小时的细胞内转运时间。
The biosynthesis and localization of fibronectin during chick muscle differentiation are described. Two monoclonal antibodies were employed, one that selectively killed mononucleated cells and one specific for avian fibronectin. These antibodies allowed precise analyses of fibronectin expression in well-defined cultures of myoblasts or myotubes and avoided the complications of exogenous fibronectin and contamination by fibroblasts or unfused myoblasts. Fibronectin synthesis, as a fraction of total protein synthesis, remains constant at 0.3-0.4% before and after myoblast fusion, suggesting that the absolute rate of fibronectin synthesis may increase somewhat when myotubes synthesize and accumulate myofibrillar proteins. The pattern of fibronectin arrangement does change during myogenesis. In myotube cultures, the appearance of pulse-labeled fibronectin at the cell surface and its secretion into the medium begin after a 2 to 3-h lag period, in contrast to the 30-min lag period observed in fibroblast cultures. This lag between polypeptide biosynthesis and the exteriorization of the new protein is thus a characteristic of each cell type rather than of the protein. All of the major secretory proteins of myogenic cells, including fibronectin and collagenous components, share this 2 to 3-h intracellular transit time.