Unicellular organisms live under diverse stressful conditions and must respond and adapt quickly to these stresses. When these stresses persist, cells favor a transition to quiescence. There are changes to many processes when cells begin their entry into quiescence. It has been reported that Hsp82 plays an important role in several such processes, and its distribution and activity change according to nutrient conditions. In this study, we found that the subcellular distribution of Hsp82 is regulated by its co-chaperone Ppt1. Under starvation conditions, Ppt1 expression was significantly reduced by a TOR-independent pathway. Furthermore, we found that Ppt1 regulates Hsp82 distribution in the cytoplasm and nucleus by dephosphorylating the S485 residue on Hsp82. The Hsp82^S485A strain has impaired membrane-related protein transport, and its cell size did not become larger in quiescence compared to log phase, resulting in failure to survive during starvation.

单细胞生物生活在各种压力条件下，必须迅速应对并适应这些压力。当这些压力持续存在时，细胞便倾向于过渡到静止状态。当细胞开始进入静止状态时，许多过程都会发生变化。据报道，Hsp82在几个这样的过程中起重要作用，其分布和活性根据营养条件而变化。在这项研究中，我们发现Hsp82的亚细胞分布受其协同伴侣Ppt1调控。在饥饿条件下，Ppt1表达通过不依赖TOR的途径显着降低。此外，我们发现Ppt1通过使Hsp82上的S485残基去磷酸化来调节Hsp82在细胞质和细胞核中的分布。Hsp82 ^S485A 菌株已经损害了与膜相关的蛋白质运输，并且其细胞大小在静止时与对数期相比没有变大，导致饥饿期间无法存活。