Proteolytic control of mitochondrial protein translocases

Abstract

Mitochondria are essential organelles that drive numerous cellular processes, including energy metabolism, ion homeostasis, and programmed cell death. This functional versatility relies on a highly dynamic proteome whose composition is continuously remodeled to meet changing cellular and environmental demands. Central to this remodeling are mitochondrial proteases (termed mitoproteases), which maintain protein quality and regulate mitochondrial function through selective processing and degradation events. Their activity ensures rapid degradation of regulatory proteins and dynamically adjusts components of multiprotein complexes. Among their most critical targets are elements of the mitochondrial protein import machinery. By modulating translocase stability and by processing preproteins during translocation, mitoproteases enable precise control over the organelle's proteome, aligning mitochondrial function with the cell's metabolic state. This review discusses how mitoproteases maintain translocase integrity and dynamically regulate mitochondrial protein import and the mitochondrial proteome.