Huang C F, Lee Y S, Schmidt M M, Schmidt J
Department of Biochemistry and Cell Biology, State University of New York at Stony Brook 11794.
EMBO J. 1994 Feb 1;13(3):634-40. doi: 10.1002/j.1460-2075.1994.tb06301.x.
In investigating the coupling of depolarization and transcription in skeletal muscle we have focused on how protein kinase C suppresses acetylcholine receptor subunit genes. The activity of acetylcholine receptor subunit promoters in non-muscle cells co-transfected with myogenic factors and E proteins was measured, and their response to protein kinase C activation analyzed. To simplify interpretation of results, gene activities rather than levels of reporter enzymes were assayed, transcriptional effects of phorbol esters were determined, with drug exposures brief enough to preclude kinase depletion, and analysis was carried out with HeLa cells, which are not liable to myogenic conversion. Myogenin, which had been postulated previously to play a role in denervation supersensitivity (Neville et al., Mol. Cell. Neurobiol., 12, 511-527, 1992), was found to be the only myogenic factor whose inactivation kinetics can account for the plasma membrane-protein kinase C-receptor gene cascade observed in intact muscle (Huang et al., Neuron, 9, 671-678, 1992).
在研究骨骼肌中去极化与转录的偶联时，我们着重关注蛋白激酶C如何抑制乙酰胆碱受体亚基基因。测定了与肌源性因子和E蛋白共转染的非肌肉细胞中乙酰胆碱受体亚基启动子的活性，并分析了它们对蛋白激酶C激活的反应。为简化结果解释，测定的是基因活性而非报告酶水平，确定佛波酯的转录效应，药物暴露时间足够短以避免激酶耗竭，并使用不易发生肌源性转化的HeLa细胞进行分析。肌细胞生成素此前被推测在去神经超敏反应中起作用（Neville等人，《分子与细胞神经生物学》，12卷，511 - 527页，1992年），结果发现它是唯一一种其失活动力学能够解释在完整肌肉中观察到的质膜 - 蛋白激酶C - 受体基因级联反应的肌源性因子（Huang等人，《神经元》，9卷，671 - 678页，1992年）。
