Chen Ming-Shun, Goswami Prabhat C, Laszlo Andrei
Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO 63108, USA.
Cell Stress Chaperones. 2002 Jan;7(1):65-72. doi: 10.1379/1466-1268(2002)007<0065:daousa>2.0.co;2.
We have previously characterized the unique organization of the U14 small nucleolar ribonucleic acid (snoRNA) gene in Chinese hamster HA-1 cells. The single copy of the hsc70/U14 gene is the only source for the production of both U14 snoRNA species and hsc70 messenger ribonucleic acid (mRNA) in these cells. Here we report that the accumulations of U14 snoRNA and hsc70 mRNA are different in response to various stress conditions, although both of them are transcribed in a single primary transcript. Heat shock induced an increased accumulation of both U14 snoRNA and hsc70 mRNA. On the other hand, exposure to sodium arsenite or azetidine induced an increased accumulation of hsc70 mRNA, but did not lead to a concomitant increase in the level of U14 snoRNA. Under normal growth conditions, the variations in the levels of U14 snoRNA and hsc70 mRNA, in the different phases of the cell cycle, are correlated. The increased expression of U14 snoRNA and hsc70 mRNA, and the hsc70 protein induced specifically by heat shock suggest that they participate in the repair process of heat-induced damage to macromolecular complexes involved in the synthesis and processing of ribosomal RNA.
我们之前已对中国仓鼠HA-1细胞中U14小核仁核糖核酸（snoRNA）基因的独特组织方式进行了表征。hsc70/U14基因的单拷贝是这些细胞中产生U14 snoRNA种类和hsc70信使核糖核酸（mRNA）的唯一来源。在此我们报告，尽管U14 snoRNA和hsc70 mRNA均由单一初级转录本转录而来，但它们在应对各种应激条件时的积累情况有所不同。热休克诱导U14 snoRNA和hsc70 mRNA的积累均增加。另一方面，暴露于亚砷酸钠或氮杂环丁烷会诱导hsc70 mRNA的积累增加，但不会导致U14 snoRNA水平随之升高。在正常生长条件下，细胞周期不同阶段中U14 snoRNA和hsc70 mRNA水平的变化是相关的。热休克特异性诱导的U14 snoRNA、hsc70 mRNA以及hsc70蛋白表达增加，表明它们参与了热诱导的对核糖体RNA合成和加工中涉及的大分子复合物损伤的修复过程。
