Cytochrome c oxidase biogenesis - from translation to early assembly of the core subunit COX1

Mitochondria are the powerhouses of the cell as they produce the majority of ATP with their oxidative phosphorylation (OXPHOS) machinery. The OXPHOS system is composed of the F1Fo ATP synthase and four mitochondrial respiratory chain complexes, the terminal enzyme of which is the cytochrome c oxidase (complex IV) that transfers electrons to oxygen, generating water. Complex IV comprises of 14 structural subunits of dual genetic origin: while the three core subunits are mitochondrial encoded, the remaining constituents are encoded by the nuclear genome. Hence, the assembly of complex IV requires the coordination of two spatially separated gene expression machinery. Recent efforts elucidated an increasing number of proteins involved in mitochondrial gene expression, which are linked to complex IV assembly. Additionally, several COX1 biogenesis factors have been intensively biochemically investigated and an increasing number of structural snapshots shed light on the organization of macromolecular complexes such as the mitoribosome or the cytochrome c oxidase. Here, we focus on COX1 translation regulation and highlight the advanced understanding of early steps during COX1 assembly and its link to mitochondrial translation regulation.

Automated summary

Mitochondria are responsible for producing the majority of ATP through their oxidative phosphorylation machinery. The complex IV, cytochrome c oxidase, is the terminal enzyme of the mitochondrial respiratory chain and transfers electrons to oxygen to generate water. Assembly of complex IV requires coordination between two gene expression machinery due to their dual genetic origin. Recent research has increased our understanding of proteins involved in mitochondrial gene expression and their role in complex IV assembly.