Arabidopsis mtHSC70-1 physically interacts with the Cox2 subunit of cytochrome c oxidase

Abstract

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 c oxidase (COX)-dependent respiration and redox homeostasis in Arabidopsis thaliana. Defects in COX assembly were observed in the mtHSC70-1 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 mtHSC70-1 mutants. Here, we further detected the interaction between mtHSC70-1 and Cox2 proteins through coimmunoprecipitation, pull-down and firefly luciferase complementation imaging assays. The results showed that mtHSC70-1 could directly combine Cox2 in vivo and in vitro, providing supporting evidence for the role of mtHSC70-1 in COX assembly.

Mitochondrial HSC70-1 Regulates Polar Auxin Transport through ROS Homeostasis in Arabidopsis Roots

“…Our previous results [ 47 , 48 ] and the data presented here support a working model in which mtHSC70-1 acts to assist respiratory chain complex IV assembly/activity and regulate ROS homeostasis, which maintains normal PAT and regulates plant growth and development ( Figure 11 ).…”

“…A. thaliana mtHSC70-1 has weak ATPase activity, which is stimulated by mitochondrial J-domain protein AtDjB1 [ 46 ]. Wei et al [ 47 ] and Zhai et al [ 48 ] reported that A. thaliana mtHSC70-1 knockout leads to severe growth inhibition and an increase in mitochondrial ROS levels during the vegetative growth of plants and that mtHSC70-1 is directly involved in respiratory chain complex IV/cytochrome c oxidase (COX) assembly and the establishment of COX-dependent respiration. Li et al [ 49 ] reported that A. thaliana mtHSC70-1 knockout impairs embryo development, and this effect is mediated by auxin.…”

Combined transcriptomic and metabolomic analyses of high temperature stress response of quinoa seedlings

“…et al 2020. [ 22 ] ZmHsf05 Zea mays ZmHsf05 plays an important role in both basal and acquired temperature tolerance in plants. Li GL.et al 2019 [ 23 ] ZmHsf01 Zea mays Lines overexpressing ZmHsf01 showed higher chlorophyll content and survival rate after HS Zhang H. et al 2020 [ 24 ] ZmHsf17 Zea mays Binds to the promoter of small heat shock proteins Qi H. et al 2022 [ 25 ].…”