MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
Nat Commun. 2020 Sep 17;11(1):4706. doi: 10.1038/s41467-020-18330-x.
Yeast physiology is temporally regulated, this becomes apparent under nutrient-limited conditions and results in respiratory oscillations (YROs). YROs share features with circadian rhythms and interact with, but are independent of, the cell division cycle. Here, we show that YROs minimise energy expenditure by restricting protein synthesis until sufficient resources are stored, while maintaining osmotic homeostasis and protein quality control. Although nutrient supply is constant, cells sequester and store metabolic resources via increased transport, autophagy and biomolecular condensation. Replete stores trigger increased H export which stimulates TORC1 and liberates proteasomes, ribosomes, chaperones and metabolic enzymes from non-membrane bound compartments. This facilitates translational bursting, liquidation of storage carbohydrates, increased ATP turnover, and the export of osmolytes. We propose that dynamic regulation of ion transport and metabolic plasticity are required to maintain osmotic and protein homeostasis during remodelling of eukaryotic proteomes, and that bioenergetic constraints selected for temporal organisation that promotes oscillatory behaviour.
酵母生理学是时间调节的,这种调节在营养有限的条件下变得明显,导致呼吸振荡(YROs)。YROs 与昼夜节律具有相似的特征,并与细胞分裂周期相互作用,但独立于细胞分裂周期。在这里,我们表明,YROs 通过限制蛋白质合成直到储存足够的资源来最小化能量消耗,同时维持渗透平衡和蛋白质质量控制。尽管营养供应是恒定的,但细胞通过增加运输、自噬和生物分子凝聚来隔离和储存代谢资源。充足的储存物触发 H 出口增加,刺激 TORC1 并将蛋白酶体、核糖体、伴侣蛋白和代谢酶从非膜结合区室中释放出来。这促进了翻译突发、储存碳水化合物的消耗、ATP 周转率的增加以及渗透物的输出。我们提出,动态调节离子运输和代谢可塑性对于维持真核生物蛋白质组重塑过程中的渗透和蛋白质平衡是必需的,生物能量限制选择了促进振荡行为的时间组织。