Endo T, Nadal-Ginard B
Cell. 1987 May 22;49(4):515-26. doi: 10.1016/0092-8674(87)90454-5.
When rat skeletal muscle cells were treated with EGTA, an inhibitor of cell fusion, a battery of muscle-specific mRNAs was synthesized but not translated despite the synthesis of many other proteins. Most of the muscle-specific mRNAs were associated with polysomes in fused myotubes, whereas they were found in postpolysomal fractions in EGTA-treated cells. Therefore, in addition to the well-documented transcriptional and posttranscriptional control of muscle-specific genes, translational control of this specific group of genes, presumably involving a Ca2+-dependent process, is also observed in these fusion-blocked cells. These findings and results obtained with other fusion inhibitors demonstrate that three types of muscle-specific gene expression take place in the fusion-blocked cells depending on the inhibitors used: one, neither muscle-specific mRNAs nor proteins are synthesized; two, the mRNAs are synthesized but not translated; and three, both the mRNAs and the proteins are synthesized.
当用细胞融合抑制剂乙二醇双四乙酸（EGTA）处理大鼠骨骼肌细胞时，尽管合成了许多其他蛋白质，但一系列肌肉特异性mRNA被合成却未被翻译。大多数肌肉特异性mRNA在融合的肌管中与多核糖体相关联，而在经EGTA处理的细胞中它们存在于多核糖体后组分中。因此，除了肌肉特异性基因已被充分证明的转录和转录后调控外，在这些融合受阻的细胞中也观察到了这一特定基因群的翻译调控，推测这涉及一个钙依赖过程。这些发现以及使用其他融合抑制剂获得的结果表明，根据所使用的抑制剂不同，在融合受阻的细胞中会发生三种类型的肌肉特异性基因表达：其一，既不合成肌肉特异性mRNA也不合成蛋白质；其二，mRNA被合成但未被翻译；其三，mRNA和蛋白质均被合成。
