Roche Benjamin, Arcangioli Benoit, Martienssen Robert
a Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA.
b Genome Dynamics Unit , UMR 3525 CNRS, Institut Pasteur, 25-28 rue du Docteur Roux , Paris , France.
RNA Biol. 2017 Jul 3;14(7):843-853. doi: 10.1080/15476286.2017.1327510. Epub 2017 May 12.
Most cells in nature are not actively dividing, yet are able to return to the cell cycle given the appropriate environmental signals. There is now ample evidence that quiescent G0 cells are not shut-down but still metabolically and transcriptionally active. Quiescent cells must maintain a basal transcriptional capacity to maintain transcripts and proteins necessary for survival. This implies a tight control over RNA polymerases: RNA pol II for mRNA transcription during G0, but especially RNA pol I and RNA pol III to maintain an appropriate level of structural RNAs, raising the possibility that specific transcriptional control mechanisms evolved in quiescent cells. In accordance with this, we recently discovered that RNA interference is necessary to control RNA polymerase I transcription during G0. While this mini-review focuses on yeast model organisms (Saccharomyces cerevisiae and Schizosaccharomyces pombe), parallels are drawn to other eukaryotes and mammalian systems, in particular stem cells.
自然界中的大多数细胞并非处于活跃分裂状态,但在受到适当的环境信号刺激时能够重新进入细胞周期。现在有充分的证据表明,静止的G0期细胞并非处于关闭状态,而是仍然具有代谢和转录活性。静止细胞必须维持基本的转录能力,以维持生存所需的转录本和蛋白质。这意味着对RNA聚合酶进行严格控制:在G0期,RNA聚合酶II用于mRNA转录,但特别是RNA聚合酶I和RNA聚合酶III用于维持适当水平的结构RNA,这增加了静止细胞中可能进化出特定转录控制机制的可能性。与此一致的是,我们最近发现RNA干扰对于在G0期控制RNA聚合酶I转录是必要的。虽然这篇小型综述主要关注酵母模式生物(酿酒酵母和裂殖酵母),但也会与其他真核生物和哺乳动物系统,特别是干细胞进行对比。