TOR regulates late steps of ribosome maturation in the nucleoplasm via Nog1 in response to nutrients
TOR regulates late steps of ribosome maturation in the nucleoplasm via Nog1 in response to nutrients
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DOI：
10.1038/sj.emboj.7601262
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发表时间：
2006-08-23
期刊：
影响因子：
11.4
通讯作者：
Ushimaru, Takashi
中科院分区：
文献类型：
--
作者：
Honma, Yoshimi;Kitamura, Aiko;Ushimaru, Takashi
蛋白激酶TOR(雷帕霉素的靶标)控制着酿酒酵母中核糖体生物发生的几个步骤，包括rRNA和核糖体蛋白的基因表达，以及35S rRNA前体的加工。在这里，我们表明，TOR也通过核GTP结合蛋白Nog1调节核糖体成熟的后期。Nog1形成了一个复合体，包括60S核糖体蛋白和核糖体前蛋白Nop7和Rlp24。Nog1复合体穿梭于核糖体生物发生的核仁和核质之间，但由于营养耗竭和TOR失活而被拴在核仁上，导致核糖体生物发生的后期停止。此外，在此之后，Nog1和Nop7蛋白丢失，导致核糖体完全停止成熟。因此，Nog1复合体是TOR介导的核糖体生物发生的关键调节因子。这是第一次描述核糖体前复合体的核仁到核质转位的生理调节。
The protein kinase TOR (target of rapamycin) controls several steps of ribosome biogenesis, including gene expression of rRNA and ribosomal proteins, and processing of the 35S rRNA precursor, in the budding yeast Saccharomyces cerevisiae. Here we show that TOR also regulates late stages of ribosome maturation in the nucleoplasm via the nuclear GTP-binding protein Nog1. Nog1 formed a complex that included 60S ribosomal proteins and pre-ribosomal proteins Nop7 and Rlp24. The Nog1 complex shuttled between the nucleolus and the nucleoplasm for ribosome biogenesis, but it was tethered to the nucleolus by both nutrient depletion and TOR inactivation, causing cessation of the late stages of ribosome biogenesis. Furthermore, after this, Nog1 and Nop7 proteins were lost, leading to complete cessation of ribosome maturation. Thus, the Nog1 complex is a critical regulator of ribosome biogenesis mediated by TOR. This is the first description of a physiological regulation of nucleolus-to-nucleoplasm translocation of pre-ribosome complexes.