College of Life Science, Hebei Normal University, Shijiazhuang, China.
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Plant Signal Behav. 2020;15(2):1714189. doi: 10.1080/15592324.2020.1714189. Epub 2020 Jan 14.
The 70-kD heat shock proteins (HSP70s or HSC70s) function as molecular chaperones and are involved in diverse cellular processes. We recently demonstrated the roles of mitochondrial HSC70-1 (mtHSC70-1) in the establishment of cytochrome oxidase (COX)-dependent respiration and redox homeostasis in . Defects in COX assembly were observed in the knockout lines. The levels of Cox2 (COX subunit 2) proteins in COX complex were markedly lower in the mutants than in wild-type plants; however, the levels of total Cox2 proteins in the mutants were not obviously different from those in wild-type plants, suggesting that the stability of COX or the availability of Cox2 was impaired in the mutants. Here, we further detected the interaction between mtHSC70-1 and Cox2 proteins through co-immunoprecipitation, pull-down and firefly luciferase complementation imaging assays. The results showed that mtHSC70-1 could directly combine Cox2 and , providing supporting evidence for the role of mtHSC70-1 in COX assembly.
70kDa 热休克蛋白（HSP70s 或 HSC70s）作为分子伴侣发挥作用，并参与多种细胞过程。我们最近证明了线粒体 HSC70-1（mtHSC70-1）在建立细胞色素氧化酶（COX）依赖性呼吸和氧化还原平衡中的作用。在 敲除系中观察到 COX 组装缺陷。与野生型植物相比，突变体中 COX 复合体的 Cox2（COX 亚基 2）蛋白水平明显降低；然而，突变体中总 Cox2 蛋白的水平与野生型植物没有明显差异，这表明 COX 的稳定性或 Cox2 的可用性在 突变体中受到损害。在这里，我们通过免疫共沉淀、下拉和萤火虫荧光素酶互补成像实验进一步检测了 mtHSC70-1 与 Cox2 蛋白之间的相互作用。结果表明，mtHSC70-1 可以直接与 Cox2 结合，为 mtHSC70-1 在 COX 组装中的作用提供了证据。
