Fig. 2. MSS51 is required for translation of ARG8m when it is inserted at COX1. (A) Growth phenotypes. Relevant nuclear and mitochondrial genotypes are indicated on the left and right side of the panel, respectively. Yeast cells were grown on YPD and replica plated to glucose minimal medium containing (+Arg) or lacking (–Arg) arginine, and complete non-fermentable medium containing ethanol and glycerol (YPEG) as indicated. Cells carrying the nuclear-encoded ARG8 gene were used for arginine growth comparison (ARG8). Cells were grown for 2 days at 30°C. (B) Steady-state accumulation of the reporter Arg8p. A 25µg aliquot of total mitochondrial proteins was separated by 12.5% SDS–PAGE, and the western blot was probed with anti-Arg8p antibody. The membrane was stripped and reprobed with antibody against citrate synthase as a loading control. An arg8 null mutant (arg8Δ) was used as a negative control. Strain details are given in the Supplementary data.