Fig. 6: The levels and the size of the CHCHD2-CHCHD10 protein complex are modulated in response to mitochondrial damage.

A Schematic representation of models with mitochondrial dysfunction. The image was created with BioRender.com. B Levels of MTHFD2, CHCHD2, and CHCHD10 (Log₂FC) obtained using publicly available proteomic datasets from tissue-specific knockout mouse strains with impaired mtDNA gene expression (Twinkle, Tefm, Mterf4 and Tfam knockout mice) and in HEK293T cell lines lacking complex I accessory subunits. C Complex I and IV in-gel activities performed on mitochondria isolated from heart tissue of RNaseH1 mice at 24 weeks of age, skeletal muscle (gastrocnemius) of Tfam mice at 5 months of age and liver of IMT treated mice for four weeks and respective controls. BN-PAGE were stained with Coomassie or incubated with substrates for detecting the in-gel activity of the indicated OXPHOS complexes. D Western Blot analysis of CHCHCD2 and CHCHD10 steady-state levels in mitochondria isolated from tissues of three different mouse strains affected by mitochondrial dysfunction in heart, skeletal muscle and liver, respectively. VDAC and Coomassie staining were used as loading controls. E Chchd2 and Chchd10 mRNA levels measured by qPCR from RNA isolated from mouse tissues with mitochondrial dysfunction. Data are represented as mean ± SEM. n = 5 mice for each genotype, *p < 0.05. F 2D-PAGE of mitochondria isolated from skeletal muscle of from heart tissue of RNaseH1 mice at 24 weeks of age, skeletal muscle (gastrocnemius) of Tfam mice at 5 months of age and liver of IMT treated mice for four weeks and respective controls Mitochondria were solubilized using 1% (w/v) DDM. The position of SDHA, ATP5, MT-CO1, MT-CO2 (used in models of mitochondrial dysfunction) and CHCHD3 (indicated by a red arrow) corresponds to the size of their different protein complexes (in kDa). P32 is indicated by blue arrows.