Functional role of respiratory supercomplexes in mice: SCAF1 relevance and segmentation of the Q<sub>pool</sub>.

Calvo, Enrique; Cogliati, Sara; Hernansanz-Agustín, Pablo; Loureiro-López, Marta; Guarás, Adela; Casuso, Rafael A; García-Marqués, Fernando; Acín-Pérez, Rebeca et al. · Sci Adv · 2020

basic_science · Level V

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Abstract

Mitochondrial respiratory complexes assemble into supercomplexes (SC). Q-respirasome (III<sub>2</sub> + IV) requires the supercomplex assembly factor (SCAF1) protein. The role of this factor in the N-respirasome (I + III<sub>2</sub> + IV) and the physiological role of SCs are controversial. Here, we study C57BL/6J mice harboring nonfunctional SCAF1, the full knockout for SCAF1, or the wild-type version of the protein and found that exercise performance is SCAF1 dependent. By combining quantitative data-independent proteomics, 2D Blue native gel electrophoresis, and functional analysis of enriched respirasome fractions, we show that SCAF1 confers structural attachment between III<sub>2</sub> and IV within the N-respirasome, increases NADH-dependent respiration, and reduces reactive oxygen species (ROS). Furthermore, the expression of AOX in cells and mice confirms that CI-CIII superassembly segments the CoQ in two pools and modulates CI-NADH oxidative capacity.