Maf1 is involved in coupling carbon metabolism to RNA polymerase III transcription
Maf1 is involved in coupling carbon metabolism to RNA polymerase III transcription
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DOI：
10.1128/mcb.01051-07
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发表时间：
2007-11-01
影响因子：
5.3
通讯作者：
Boguta, Magdalena
中科院分区：
文献类型：
--
作者：
Ciesla, Malgorzata;Towpik, Joanna;Boguta, Magdalena
RNA聚合酶III（Pol III）产生生物合成机制的必需组分，因此其活性与细胞生长和代谢紧密相关。Maf 1是酿酒酵母（Saccharomyces cerevisiae）中唯一已知的全局性和直接性Pol III转录抑制因子，它介导了许多应激信号。在这里，我们证明Maf 1的转录调控不仅限于应激，而且对发酵和呼吸之间的转换很重要。在呼吸条件下，Maf 1通过去磷酸化被激活并输入到细胞核中。从不可发酵的碳源到葡萄糖的碳源的转变诱导Maf 1磷酸化并将其重新定位到细胞质。Maf 1介导的tRNA合成控制的缺乏损害了不可发酵碳源中的细胞活力。Maf 1-Delta的呼吸表型允许遗传抑制研究来剖析Maf 1对Pol III转录装置的作用机制。此外，在不可发酵碳源中生长的细胞中，Maf 1在不同程度上调节不同tRNA的水平。调节的差异可能有助于人的生理作用。
RNA polyrnerase III (Pol III) produces essential components of the biosynthetic machinery, and therefore its activity is tightly coupled with cell growth and metabolism. In the yeast Saccharomyces cerevisiae, Maf1 is the only known global and direct Pol III transcription repressor which mediates numerous stress signals. Here we demonstrate that transcription regulation by Maf1 is not limited to stress but is important for the switch between fermentation and respiration. Under respiratory conditions, Maf1 is activated by dephosphorylation and imported into the nucleus. The transition from a nonfermentable carbon source to that of glucose induces Maf1 phosphoryllation and its relocation to the cytoplasm. The absence of Maf1-mediated control of tRNA synthesis impairs cell viability in nonfermentable carbon sources. The respiratory phenotype of maf1-Delta allowed genetic suppression studies to dissect the mechanism of Maf1 action on the Pol III transcription apparatus. Moreover, in cells grown in a nonfermentable carbon source, Maf1 regulates the levels of different tRNAs to various extents. The differences in regulation may contribute to the physiological role of Man.