Between 6-20% of the cellular proteome is under circadian control to tune cell function with cycles of environmental change. For cell viability, and to maintain volume within narrow limits, the osmotic pressure exerted by changes in the soluble proteome must be compensated. The mechanisms and consequences underlying compensation are not known. Here, we show in cultured mammalian cells and in vivo that compensation requires electroneutral active transport of Na+, K+, and Cl- through differential activity of SLC12A family cotransporters. In cardiomyocytes ex vivo and in vivo, compensatory ion fluxes alter their electrical activity at different times of the day. Perturbation of soluble protein abundance has commensurate effects on ion composition and cellular function across the circadian cycle. Thus, circadian regulation of the proteome impacts ion homeostasis with substantial consequences for the physiology of electrically active cells such as cardiomyocytes.

中文翻译：

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补偿性离子转运缓冲日常蛋白质节律，以调节渗透平衡和细胞生理

在昼夜节律控制下，有6-20％的细胞蛋白质组随着环境变化的周期而调节细胞功能。为了使细胞存活并保持体积在狭窄范围内，必须补偿可溶性蛋白质组的变化所产生的渗透压。补偿的机制和后果尚不清楚。在这里，我们在培养的哺乳动物细胞和体内显示，补偿需要通过SLC12A家族共转运蛋白的不同活性来进行Na +，K +和Cl-的电中性主动转运。在离体和体内心肌细胞中，代偿性离子通量会在一天的不同时间改变其电活动。可溶性蛋白丰度的扰动在昼夜节律周期中对离子组成和细胞功能具有相称的影响。从而，