Fig. 4. Western blot analysis after SDS–PAGE separation of mitochondrial membranes (20 µg) and isolated QCR (2 pmol) from yeasts expressing wild-type and mutated CYT1 (K272A). K272 is the stabilizing ligand of the interhelical phospholipid (L3). RIP1, COB and CYT1 were detected using specific antibodies.