Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, UMR 5095, F-33000 Bordeaux, France.
J Cell Biol. 2011 Mar 21;192(6):949-57. doi: 10.1083/jcb.201009028. Epub 2011 Mar 14.
Quiescence is defined as a temporary arrest of proliferation, yet it likely encompasses various cellular situations. Our knowledge about this widespread cellular state remains limited. In particular, little is known about the molecular determinants that orchestrate quiescence establishment and exit. Here we show that upon carbon source exhaustion, budding yeast can enter quiescence from all cell cycle phases. Moreover, using cellular structures that are candidate markers for quiescence, we found that the first steps of quiescence exit can be triggered independently of cell growth and proliferation by the sole addition of glucose in both Saccharomyces cerevisiae and Schizosaccharomyces pombe. Importantly, glucose needs to be internalized and catabolized all the way down to glycolysis to mobilize quiescent cell specific structures, but, strikingly, ATP replenishment is apparently not the key signal. Altogether, these findings strongly suggest that quiescence entry and exit primarily rely on cellular metabolic status and can be uncoupled from the cell cycle.
静止期被定义为增殖的暂时停滞，但它可能包含各种细胞状态。我们对这种广泛存在的细胞状态的了解仍然有限。特别是，关于协调静止期建立和退出的分子决定因素知之甚少。在这里，我们表明，当碳源耗尽时，出芽酵母可以从所有细胞周期阶段进入静止期。此外，使用可能作为静止期候选标记的细胞结构，我们发现，仅在酿酒酵母和裂殖酵母中添加葡萄糖，就可以独立于细胞生长和增殖来触发静止期退出的最初步骤。重要的是，葡萄糖需要被内化并代谢到糖酵解才能动员静止期细胞的特异性结构，但令人惊讶的是，ATP 的补充显然不是关键信号。总的来说，这些发现强烈表明静止期的进入和退出主要依赖于细胞代谢状态，可以与细胞周期脱耦。
