Metsikkö K, Väänänen H K
Department of Anatomy, University of Oulu, Finland.
Int J Dev Biol. 1993 Jun;37(2):305-10.
Rat L6 myoblastic cell line fused rapidly after two day cultivation in a medium containing horse serum and insulin. We analyzed whether the induction of plasma membrane or secreted proteins occurred simultaneously with ongoing fusion. Thus the cells were metabolically labeled with [35S]methionine followed by biotinylation of the cell surface proteins. Detergent-solubilized proteins derivatized with biotin were isolated with streptavidin-agarose and subjected to SDS polyacrylamide gel electrophoresis. This analysis did not show fusion-associated induction of any surface proteins. However, analysis of the microsomal fraction revealed a fusion-associated 38-kDa glycopolypeptide. This polypeptide appeared simultaneously with the formation of the multinucleated cells and then declined with decreasing fusion activity. Pulse-chase labeling experiments showed that the 38-kDa component was secreted into the medium. These results indicate that a secreted protein component is induced during the fusion of L6 myoblasts.
大鼠L6成肌细胞系在含有马血清和胰岛素的培养基中培养两天后迅速融合。我们分析了质膜或分泌蛋白的诱导是否与正在进行的融合同时发生。因此，细胞用[35S]甲硫氨酸进行代谢标记，随后对细胞表面蛋白进行生物素化。用链霉亲和素-琼脂糖分离生物素化的去污剂溶解蛋白，并进行SDS聚丙烯酰胺凝胶电泳。该分析未显示任何表面蛋白的融合相关诱导。然而，微粒体部分的分析揭示了一种与融合相关的38 kDa糖多肽。这种多肽与多核细胞的形成同时出现，然后随着融合活性的降低而下降。脉冲追踪标记实验表明，38 kDa成分分泌到培养基中。这些结果表明，在L6成肌细胞融合过程中诱导了一种分泌蛋白成分。
