Proteolytic coordination of the OXPHOS Life Cycle.

Abstract

The mitochondrial oxidative phosphorylation (OXPHOS) system consists of multimeric, highly ordered protein complexes critical for energy production and metabolic wiring in the cell. Recent discoveries in mitochondrial proteolysis, facilitated by advances in proteomic approaches, have transformed the view of mitochondrial proteases from a simple quality-control system into a dynamically coordinated network of enzymes that actively shape the status of the OXPHOS machinery. Mapping OXPHOS-associated proteolytic circuits has uncovered specialized functions of individual proteases and identified key interaction sites. The present review outlines how mitochondrial proteases regulate the OXPHOS life cycle: expression, delivery, assembly, long-term maintenance, and disposal of mitochondrial respiratory complexes. We summarize past findings and highlight emerging concepts, including asynchronous OXPHOS turnover, cofactor-driven proteolysis, and bioenergetics-coupled degradation. Progress in these areas will deepen our understanding of how proteases coordinate the OXPHOS life cycle.