Allotopic expression of COX6 elucidates Atco-driven co-assembly of cytochrome oxidase and ATP synthase

Author(s)

Franco, Leticia Veloso R. ; Su, Chen-Hsien ; Teixeira, Lorisa Simas ; Chagas, Jhulia Almeida Clarck ; Barros, Mario Henrique ; Tzagoloff, Alexander

• Document type: Journal article
• Source: LIFE SCIENCE ALLIANCE; v. 6, n. 11, p. 15-pg., 2023-11-01.

Abstract

The Cox6 subunit of Saccharomyces cerevisiae cytochrome oxidase (COX) and the Atp9 subunit of the ATP synthase are encoded in nuclear and mitochondrial DNA, respectively. The two proteins interact to form Atco complexes that serve as the source of Atp9 for ATP synthase assembly. To determine if Atco is also a precursor of COX, we pulse-labeled Cox6 in isolated mitochondria of a cox6 nuclear mutant with COX6 in mitochondrial DNA. Only a small fraction of the newly translated Cox6 was found to be present in Atco, which can explain the low concentration of COX and poor complementation of the cox6 mutation by the allotopic gene. This and other pieces of evidence presented in this study indicate that Atco is an obligatory source of Cox6 for COX biogenesis. Together with our finding that atp9 mutants fail to assemble COX, we propose a regulatory model in which Atco unidirectionally couples the biogenesis of COX to that of the ATP synthase to maintain a proper ratio of these two complexes of oxidative phosphorylation. (AU)

• FAPESP's process: 19/16015-3 - ATCO1, a mitochondrial master regulator of ATP Synthase and Cytochrome Oxidase biogenesis?
• Grantee: LETICIA VELOSO RIBEIRO FRANCO
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 19/02799-2 - ATCO1, a mitochondrial master regulator of ATP synthase and cytochrome oxidase biogenesis?
• Grantee: LETICIA VELOSO RIBEIRO FRANCO
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/05812-7 - Regulation events for mitoribossome biogenesis and respiratory complexes assembly
• Grantee: Mario Henrique de Barros
• Support Opportunities: Regular Research Grants