Small heat shock proteins (sHsps) are ubiquitous molecular chaperones found in all domains of life, possessing significant roles in protein quality control in cells and assisting the refolding of non-native proteins. They are efficient chaperones against many in vitro protein substrates. Nevertheless, the in vivo native substrates of sHsps are not known. To better understand the functions of sHsps and the mechanisms by which they enhance heat resistance, sHsp-interacting proteins were identified using affinity purification under heat shock conditions. This paper aims at providing some insights into the characteristics of natural substrate proteins of sHsps. It seems that sHsps of prokaryotes, as well as sHsps of some eukaryotes, can bind to a wide range of substrate proteins with a preference for certain functional classes of proteins. Using Drosophila melanogaster mitochondrial Hsp22 as a model system, we observed that this sHsp interacted with the members of ATP synthase machinery. Mechanistically, Hsp22 interacts with the multi-type substrate proteins under heat shock conditions as well as non-heat shock conditions.

中文翻译：

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与小热休克蛋白相互作用的蛋白质的结构和功能特性。


小热休克蛋白 (sHsps) 是生命各个领域中普遍存在的分子伴侣，在细胞中的蛋白质质量控​​制和协助非天然蛋白质的重折叠中发挥着重要作用。它们是针对许多体外蛋白质底物的有效伴侣。然而，sHsps 的体内天然底物尚不清楚。为了更好地了解 sHsp 的功能及其增强耐热性的机制，在热激条件下使用亲和纯化鉴定了 sHsp 相互作用蛋白。本文旨在提供有关 sHsps 天然底物蛋白特性的一些见解。原核生物的小热休克蛋白以及一些真核生物的小热休克蛋白似乎可以结合多种底物蛋白，并优先结合某些功能类别的蛋白质。使用果蝇线粒体Hsp22 作为模型系统，我们观察到该 sHsp 与 ATP 合酶机制的成员相互作用。从机制上讲，Hsp22 在热激条件和非热激条件下与多种底物蛋白相互作用。