Figure 2. Respiratory supercomplexes are impaired in Oma1-deficient yeast cells.

(A) Steady-state levels of the Cox1-Cox3 subunits of CcO (Complex IV), Cyt1 and Rip1 subunits of bc₁cytochrome c reductase (Complex III), Sdh2 subunit of succinate dehydrogenase (Complex II), and Atp2 subunit of F₁F_O ATP synthase (Complex V), and porin were assessed by immunobloting of mitochondria (20 μg) from WT and oma1Δ cells. (B) BN-PAGE of individual ETC complexes from log and stationary phase WT and oma1Δ cells. Mitochondria (40 μg) were solubilized with 1% dodecyl maltoside (DDM). The complexes were visualized by blotting with indicated antibodies. (C) BN-PAGE of the above mitochondria lysed with 1.5% digitonin. (D) oma1Δ cells bearing vector, Myc-tagged Oma1 or its H203A variant were grown in synethetic galactose medium and used for mitochondrial isolation. Mitochondria (70 μg) were analyzed by BN-PAGE as in C. Another 20 μg of mitochondria were used for SDS-PAGE. Source data (full-length blots) are available online in Supplementary information.