THE REGULATION OF RNA SYNTHESIS AND PROCESSING IN THE NUCLEOLUS DURING INHIBITION OF PROTEIN SYNTHESIS
THE REGULATION OF RNA SYNTHESIS AND PROCESSING IN THE NUCLEOLUS DURING INHIBITION OF PROTEIN SYNTHESIS
复制标题
蛋白质合成抑制过程中核仁内 RNA 合成和加工的调节
作者：
M. Willems;M. Penman;S. Penman
在HeLa细胞中研究了放线菌酮抑制蛋白质合成对核仁RNA合成和加工的影响。给药后，45 S RNA前体福尔斯的合成迅速下降。然而，45S RNA的核仁含量保持相对恒定至少1小时，因为前体分子裂解成其产物所需的时间延长后，用放线菌酮处理。45S RNA转化为32S RNA的效率保持恒定，每切割一分子45S RNA产生大约一分子32S RNA。然而，在蛋白质合成停止后不久，18S RNA的形成就失败了。核仁中32S RNA的量保持相对恒定。在长时间的蛋白质合成抑制后，28S RNA继续合成并输出到细胞质中，但速率大大降低。当去除蛋白质合成抑制剂时，45S RNA的合成速率迅速恢复，尽管是部分恢复。RNA合成调控和加工的各个方面进行了讨论。
The effect of protein synthesis inhibition by cycloheximide on nucleolar RNA synthesis and processing has been studied in HeLa cells. Synthesis of 45S RNA precursor falls rapidly after administration of the drug. However, the nucleolar content of 45S RNA remains relatively constant for at least 1 hr because the time required for cleavage of the precursor molecule into its products is lengthened after treatment with cycloheximide. The efficiency of transformation of 45S RNA to 32S RNA remains constant with approximately one molecule of the 32S RNA produced for each cleavage of a molecule of 45S RNA. However, shortly after the cessation of protein synthesis the formation of 18S RNA becomes abortive. The amount of 32S RNA present in the nucleolus remains relatively constant. After long periods of protein synthesis inhibition the 28S RNA continues to be synthesized and exported to the cytoplasm but at a greatly reduced rate. When the protein synthesis inhibitor is removed, a prompt, although partial, recovery in the synthesis rate of 45S RNA occurs. The various aspects of RNA synthesis regulation and processing are discussed.