College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu, 225009, China.
College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu, 225009, China.
Biochem Biophys Res Commun. 2022 Oct 20;626:236-242. doi: 10.1016/j.bbrc.2022.07.081. Epub 2022 Jul 31.
Heat shock proteins 70 (HSP70s) could cooperate with structurally diverse HSP40s (J proteins) to generate diverse chaperone networks in various cellular compartments, performing multiple housekeeping and stress-related functions in the organisms. There are two kinds of chloroplast heat shock protein 70 (cpHsc70-1, cpHsc70-2) and multiple J proteins in the Arabidopsis chloroplasts, while the interaction between cpHsc70s and J proteins and the function of most J proteins are largely unknown. In the present study, we found that AtDJC78 interacts with cpHsc70-1 through its C terminal, according to the results of yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC). Bioinformatics analysis showed that DJC78 is one of the widespread and highly conserved J proteins in plants, AtDJC78 could be transported into chloroplasts, and the expression of AtDJC78 was significantly up-regulated under heat stress. Furthermore, we found that AtDJC78 may be associated with regulating hydrogen peroxide levels under heat stress in plants. These findings suggest that AtDJC78 is a new cochaperone interacting with cpHsc70-1 in the chloroplasts.
热休克蛋白 70（HSP70s）可以与结构多样的 HSP40（J 蛋白）合作，在各种细胞区室中产生不同的伴侣网络，在生物体中执行多种管家和应激相关功能。拟南芥叶绿体中有两种叶绿体热休克蛋白 70（cpHsc70-1、cpHsc70-2）和多个 J 蛋白，然而 cpHsc70s 和 J 蛋白之间的相互作用以及大多数 J 蛋白的功能在很大程度上尚不清楚。在本研究中，根据酵母双杂交（Y2H）和双分子荧光互补（BiFC）的结果，我们发现 AtDJC78 通过其 C 端与 cpHsc70-1 相互作用。生物信息学分析表明，DJC78 是植物中广泛存在且高度保守的 J 蛋白之一，AtDJC78 可以被转运到叶绿体中，并且在热胁迫下 AtDJC78 的表达显著上调。此外，我们发现 AtDJC78 可能与植物中热胁迫下过氧化氢水平的调节有关。这些发现表明 AtDJC78 是与叶绿体中 cpHsc70-1 相互作用的新伴侣蛋白。
