A constricted mitochondrial morphology optimizes respiration

Abstract

AbstractMitochondria assemble in a dynamic tubular network with a morphology governed by mitochondrial fusion and fission, which regulate all mitochondrial functions including oxidative phosphorylation1–4. Yet, the link between mitochondrial morphology and respiration remains unclear5–9. Here, we discover a previously unknown mitochondrial morphology dedicated to respiratory growth ofSaccharomyces cerevisiae, which we refer to as “Ringo”. The Ringo morphology is characterized by stable constrictions of mitochondrial tubules. Ringo constrictions are mediated by the yeast dynamin Dnm1 and, unlike mitochondrial fission10–12, occur in the absence of contacts with the endoplasmic reticulum. Our data show that the Ringo morphology regulates mitochondrial DNA homeostasis during respiration to ensure stoichiometric assembly of OXPHOS complexes, demonstrating that the shape of mitochondria actively contributes to optimal respiration.One-Sentence Summary:We report a new mitochondrial morphology that actively contributes to optimal respiration in yeast.