Proteolytic regulation of mitochondrial oxidative phosphorylation components in plants

Mitochondrial function relies on the homeostasis and quality control of their proteome, including components of the oxidative phosphorylation (OXPHOS) pathway that generates energy in form of ATP. OXPHOS subunits are under constant exposure to reactive oxygen species due to their oxidation-reduction activities, which consequently make them prone to oxidative damage, misfolding, and aggregation. As a result, quality control mechanisms through turnover and degradation are required for maintaining mitochondrial activity. Degradation of OXPHOS subunits can be achieved through proteomic turnover or modular degradation. In this review, we present multiple protein degradation pathways in plant mitochondria. Specifically, we focus on the intricate turnover of OXPHOS subunits, prior to protein import via cytosolic proteasomal degradation and post import and assembly via intra-mitochondrial proteolysis involving multiple AAA+ proteases. Together, these proteolytic pathways maintain the activity and homeostasis of OXPHOS components.

Automated summary

Mitochondrial function relies on the homeostasis and quality control of their proteome, which includes the components of the oxidative phosphorylation pathway. The subunits of oxidative phosphorylation are prone to oxidative damage, misfolding, and aggregation due to their exposure to reactive oxygen species. Multiple protein degradation pathways are involved in maintaining the activity and homeostasis of oxidative phosphorylation components in plant mitochondria, including proteomic turnover and modular degradation.