Bond Ursula
Microbiology Department, Moyne Institute for Preventive Medicine, Trinity College, University of Dublin, Dublin, Ireland.
FEMS Yeast Res. 2006 Mar;6(2):160-70. doi: 10.1111/j.1567-1364.2006.00032.x.
Exposure of yeast cells to environmental stresses can disrupt essential intracellular processes, especially those carried out by large macromolecular complexes. The production of mature, translatable mRNAs is most sensitive to stress owing to the inhibition of messenger RNA splicing and alterations in the export of mRNA from the nucleus. Changes in the cytoplasmic pools of mRNAs also occur following exposure to stress conditions. Messenger RNAs accumulate in discrete cytoplasmic foci such as processing bodies and stress granules. These dynamic changes in RNA metabolism, following exposure to stress, ensure the preferential production and export of heat-shock mRNAs and the sequestering of general cellular mRNAs in the nucleus or in cytoplasmic foci, thus allowing for a redirection of the translational machinery to encode stress proteins, which aid in cellular recovery following stress. Stress proteins, such as Hsp70p and Hsp104p, have been shown to play a direct role in the repair of macromolecular complexes involved in RNA metabolism in yeast cells, thus ensuring that the cell returns to homeostasis.
将酵母细胞暴露于环境应激下会破坏重要的细胞内过程，尤其是那些由大型大分子复合物执行的过程。由于信使核糖核酸（mRNA）剪接受到抑制以及mRNA从细胞核输出的改变，成熟的、可翻译的mRNA的产生对应激最为敏感。暴露于应激条件后，细胞质中mRNA库也会发生变化。mRNA会在离散的细胞质位点积累，如加工小体和应激颗粒。应激后RNA代谢的这些动态变化确保了热休克mRNA的优先产生和输出，以及一般细胞mRNA在细胞核或细胞质位点的隔离，从而使翻译机制能够重新定向以编码应激蛋白，这些应激蛋白有助于细胞在应激后恢复。应激蛋白，如Hsp70p和Hsp104p，已被证明在酵母细胞中参与RNA代谢的大分子复合物的修复中发挥直接作用，从而确保细胞恢复到稳态。
