Regulation of Mitochondrial Electron Transport Chain Assembly.

Mitochondrial function depends on the correct synthesis, transport, and assembly of proteins and cofactors of the electron transport chain. The initial idea that the respiratory chain protein complexes (RCCs) were independent structures in the inner mitochondrial membrane evolved after the identification of higher quaternary structures called supercomplexes (SCs), whose formation is dynamically regulated in order to accommodate cellular metabolic demands. Due to the dual genetic origin of the mitochondrial proteome, electron transport chain and SCs formation must be tightly regulated to coordinate the expression and assembly of components encoded by both genomes. This regulation occurs at different levels from gene transcription to protein, complex or SCs assembly, and might involve the participation of factors that contribute to the formation and stability of the RCCs and SCs. Here we review the cellular pathways and assembly factors that regulate RCCs and SCs formation.