Research Paper Volume 5, Issue 4 pp 234—269

Figure 5. Under CR conditions, the atg32Δ mutation reduces the levels of several large protein super-complexes in the IMM, likely due to their dissociation into individual proteins or small protein subcomplexes.

WT and atg32Δ strains were cultured in the nutrient-rich YP medium initially containing 0.2% glucose. Mitochondria were purified from WT and atg32Δ cells recovered on day 4 of culturing. (A) Digitonin-solubilized protein complexes from the inner membrane of these mitochondria were separated on a linear 4-13% acrylamide gradient gel for first-dimension blue native PAGE (1-D BN-PAGE). Arrows mark the positions of protein supercomplexes 2, 3, 4 and 5 whose levels were reduced in the IMM of atg32Δ cells. (B and C) Equal quantities (10 μg) of protein from these mitochondria were subjected to first-dimension SDS-PAGE (1-D SDS-PAGE) and analyzed by quantitative immunoblotting with antibodies to porin (loading control), Cyt1p (cytochrome c1, a component of the respiratory complex III), Cox2p (subunit II of cytochrome c oxidase, a component of the respiratory complex IV) or F1α/β (alpha and beta subunits of the mitochondrial F1ATPase, the respiratory complex V). Data in C are presented as means ± SEM (n = 3-4; ns, not significant).