• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Heat shock-induced translational control of HSP70 and globin synthesis in chicken reticulocytes.
【24h】

Heat shock-induced translational control of HSP70 and globin synthesis in chicken reticulocytes.

机译：热休克诱导的鸡网织红细胞中HSP70和球蛋白合成的翻译控制。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Incubation of chicken reticulocytes at elevated temperatures (43 to 45 degrees C) resulted in a rapid change in the pattern of protein synthesis, characterized by the decreased synthesis of normal proteins, e.g., alpha and beta globin, and the preferential and increased synthesis of only one heat shock protein, HSP70. The repression of globin synthesis was not due to modifications of globin mRNA because the level of globin mRNA and its ability to be translated in vitro were unaffected. The HSP70 gene in reticulocytes was transcribed in non-heat-shocked cells, yet HSP70 was not efficiently translated until the cells had been heat shocked. In non-heat-shocked reticulocytes, HSP70 mRNA was a moderately abundant mRNA present at 1 to 2% of the level of globin mRNA. The rapid 20-fold increase in the synthesis of HSP70 after heat shock was not accompanied by a corresponding increase in the rate of transcription of the HSP70 gene or accumulation of HSP70 mRNA. These results suggest that the elevated synthesis of HSP70 is due to the preferential utilization of HSP70 mRNA in the heat-shocked reticulocyte. The heat shock-induced alterations in the reticulocyte protein-synthetic apparatus were not reversible. Upon return to control temperatures (37 degrees C), heat-shocked reticulocytes continued to synthesize HSP70 at elevated levels whereas globin synthesis continued to be repressed. Despite the presence of HSP70 mRNA in non-heat-shocked reticulocytes, we found that continued transcription was necessary for the preferential translation of HSP70 in heat-shocked cells. Preincubation of reticulocytes with the transcription inhibitor actinomycin D or 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole blocked the heat shock-induced synthesis of HSP70. Because the level of HSP70 mRNA was only slightly diminished in cells treated with actinomycin D, we suggest two possible mechanisms for the preferential translation of HSP70 mRNA: the translation of only newly transcribed HSP70 mRNA or the requirement of a newly transcribed RNA-containing factor.
机译：鸡网织红细胞在高温（43到45摄氏度）下孵育会导致蛋白质合成模式的快速变化，其特征是正常蛋白质（例如α和β珠蛋白）的合成减少，并且仅蛋白质的优先合成和增加一种热激蛋白HSP70。球蛋白合成的抑制不是由于球蛋白mRNA的修饰引起的，因为球蛋白mRNA的水平及其在体外翻译的能力不受影响。网状细胞中的HSP70基因在非热休克细胞中转录，但是HSP70直到细胞被热激后才有效翻译。在非热休克的网状细胞中，HSP70 mRNA是中等含量的mRNA，其含量为球蛋白mRNA的1-2％。热休克后HSP70的合成迅速增加20倍，但并没有相应增加HSP70基因的转录速率或HSP70 mRNA的积累。这些结果表明，HSP70的合成增加是由于热休克的网状细胞中HSP70 mRNA的优先利用。网织红细胞蛋白合成仪中热激诱导的改变是不可逆的。恢复到控制温度（37摄氏度）后，热休克的网织红细胞继续以升高的水平合成HSP70，而球蛋白的合成继续受到抑制。尽管在非热激网织红细胞中存在HSP70 mRNA，但我们发现继续转录对于热激细胞中HSP70的优先翻译是必要的。网状细胞与转录抑制剂放线菌素D或5,6-二氯-1-β-D-呋喃呋喃糖基苯并咪唑的预温育可阻止热激诱导的HSP70合成。因为在用放线菌素D处理的细胞中HSP70 mRNA的水平仅略有降低，所以我们提出了HSP70 mRNA优先翻译的两种可能的机制：仅新转录的HSP70 mRNA的翻译或需要新转录的含RNA因子的翻译。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号