Proteins are constantly challenged by environmental stress conditions that threaten their structure and function. Especially problematic are oxidative, acid, and severe heat stress which induce very rapid and widespread protein unfolding and generate conditions that make canonical chaperones and/or transcriptional responses inadequate to protect the proteome. We review here recent advances in identifying and characterizing stress-activated chaperones which are inactive under non-stress conditions but become potent chaperones under specific protein-unfolding stress conditions. We discuss the post-translational mechanisms by which these chaperones sense stress, and consider the role that intrinsic disorder plays in their regulation and function. We examine their physiological roles under both non-stress and stress conditions, their integration into the cellular proteostasis network, and their potential as novel therapeutic targets.

蛋白质不断受到威胁其结构和功能的环境压力条件的挑战。尤其成问题的是氧化，酸和严重的热应激，它们引起非常迅速和广泛的蛋白质解折叠，并产生使经典的分子伴侣和/或转录反应不足以保护蛋白质组的条件。我们在这里回顾了鉴定和表征在非应激条件下无活性但在特定的蛋白质解折叠应激条件下变成有效伴侣的应激活化分子伴侣的最新进展。我们讨论了这些伴侣感知压力的翻译后机制，并考虑了内在障碍在其调节和功能中所起的作用。我们研究了它们在非压力和压力条件下的生理作用，