Hayashi Y, Kominami R, Muramatsu M
J Biochem. 1977 Feb;81(2):451-9. doi: 10.1093/oxfordjournals.jbchem.a131478.
The synthesis and incorporation into ribosomes of 5S RNA were investigated under conditions of protein synthesis inhibition by cycloheximide. Within 1 h after addition of cycloheximide to the culture medium, the synthesis of 5S RNA in HeLa cells, as measured by the pulse labeling of total 5S RNA, was inhibited by 25-30 per cent, but the degree of inhibition did not further increase for several hours. The synthesis of 4S RNA was less markedly inhibited, especially at earlier time periods. Although the appearance of labeled 5S RNA in cytoplasmic ribosomoes after chase was inhibited by approximately 60% or more this presumably reflects the inhibition of 60S ribosomal subunit formation by cycloheximide. Some utilization of preformed 5S RNA for new ribosomes was suggested after resumption of protein synthesis. In confirmation of the results of Kumar and Wu (1), a low dose of actinomycin D inhibited the appearance of 28S RNA in the cytoplasm rather specifically, whereas cycloheximide showed an apparently opposite differential effect.
在环己酰亚胺抑制蛋白质合成的条件下，研究了5S RNA的合成及其掺入核糖体的过程。向培养基中添加环己酰亚胺后1小时内，通过对总5S RNA进行脉冲标记测定，HeLa细胞中5S RNA的合成受到25% - 30%的抑制，但在数小时内抑制程度并未进一步增加。4S RNA的合成受到的抑制不太明显，尤其是在早期阶段。尽管追踪后细胞质核糖体中标记的5S RNA的出现受到约60%或更高的抑制，但这可能反映了环己酰亚胺对60S核糖体亚基形成的抑制作用。蛋白质合成恢复后，提示有一些预先形成的5S RNA被用于新核糖体的合成。为证实Kumar和Wu（1）的结果，低剂量的放线菌素D相当特异性地抑制了28S RNA在细胞质中的出现，而环己酰亚胺则表现出明显相反的差异效应。
