Tas P W, Martini O H
Eur J Biochem. 1987 Mar 16;163(3):553-9. doi: 10.1111/j.1432-1033.1987.tb10903.x.
Decreases in energy charge, ribosomal protein phosphorylation and rate of protein synthesis are well-documented facets of the cellular response to hyperthermia in non-vertebrates. We have tried to reproduce this response pattern in 32P-labelled HeLa cells in order to investigate the hypothetical causal relationship between these effects. In HeLa cells shifted from 36 degrees C to 42 degrees C, dephosphorylation of S6 and inhibition of protein synthesis, owing to a decreased initiation rate, were observed, but could not have been mediated by changes in the cells' general energy charge since the ATP and GTP levels were not reduced. In addition, we found that the hyperthermic translation block developed faster than the overall dephosphorylation of S6, showing that S6 dephosphorylation cannot be responsible for the translation block unless site-specific effects play a critical role.
能量电荷减少、核糖体蛋白磷酸化以及蛋白质合成速率降低，是无脊椎动物细胞对热疗反应中已有充分文献记载的几个方面。我们试图在32P标记的HeLa细胞中重现这种反应模式，以研究这些效应之间假设的因果关系。在从36℃转移至42℃的HeLa细胞中，观察到S6的去磷酸化以及由于起始速率降低导致的蛋白质合成抑制，但这不可能是由细胞总体能量电荷的变化介导的，因为ATP和GTP水平并未降低。此外，我们发现热疗导致的翻译阻滞比S6的总体去磷酸化发展得更快，这表明除非位点特异性效应起关键作用，否则S6去磷酸化不可能是翻译阻滞的原因。
