FIGURE 1: Partially decreasing cytosolic translation in Taffazin-deficient (taz1Δ) yeast improves respiration-dependent growth and mtDNA maintenance. (A) taz1Δ yeast cells were spread as dense layers onto rich ethanol solid media and then exposed to sterile filters spotted with cycloheximide, anisomycin or emetine (dissolved in DMSO). The plates were scanned after 5 days of incubation at 36°C. The filter at the top left was spotted with DMSO alone to provide a negative control. (B) Determination in liquid cultures of CHX concentrations that optimally rescue taz1Δ yeast. Complete synthetic media (CSM) containing 0.5% galactose + 2% ethanol sup-plemented or not with CHX at the indicated concentrations were inoculated with WT and taz1Δ cells pre-grown in CSM containing 2% glucose at 28°C. The cultures were performed at 36°C and cells densities (OD_600nm) taken over a period of 36 hours. (C) Rate of cytosolic protein synthesis. Total proteins and mitochondrial proteins were labeled with a mixture of [³⁵S]-methionine and [³⁵S]-cysteine for 20 min in whole cells from wild type, taz1Δ rei1Δ, taz1Δ rpl6bΔ and taz1Δ yeast grown for 24 hours in rich 0.5% galactose + 2% ethanol at 36°C, and taz1Δ cells grown in the same conditions in presence of 10 nM cycloheximide (CHX). After the labeling reactions, total protein extracts were prepared and separated by SDS-PAGE on a 12% polyacrylamide gel (75 µg per lane). The gels were dried and analyzed with a PhosphorImager. Quantification was performed using Image J. Data are expressed in % relative to the WT (n=3). The shown data are cytosolic protein synthesis rates (total minus mitochondrial protein synthesis rates). Statistical analysis was done with Tukey’s test (*P<0.05; **P<0.01; ***P<0.001; ****P<0.0001). (D) Genetic ablation of REI1 (rei1Δ) or RPL6B (rpl6bΔ) improves respiratory growth of taz1Δ yeast. WT, taz1Δ, taz1Δ rei1Δ and taz1Δ rpl6bΔ cells freshly grown at 28°C in rich glucose were serially diluted and spotted onto rich ethanol and glucose plates. The plates were scanned after 4 days of incubation at the indicated temperature. (E) Growth of WT, taz1Δ, taz1Δ rei1Δ and taz1Δ rpl6bΔ strains in liquid complete synthetic media containing 0.5% galactose + 2% ethanol at 36°C. The cultures were inoculated with cells grown in CSM containing 2% glucose at 28°C. The cultures were performed at 36°C and cell densities (OD_600nm) taken over a period of 60 hours. (F) Genetic ablation of REI1 (rei1Δ) or RPL6B (rpl6bΔ) in taz1Δ yeast preserves mtDNA maintenance. Proportions of ρ^–/ρ⁰ cells produced in glucose cultures at 28°C of strains WT, taz1Δ, taz1Δ reiΔ, and taz1Δ rpl6bΔ were determined using the procedure described in [60] (n=3). Data are expressed in % relative to the WT and were statistically analyzed using Tukey’s test (*P<0.05; **P<0.01; ***P<0.001).

60. de Taffin de Tilques M, Tribouillard-Tanvier D, Tetaud E, Testet E, di Rago JP, Lasserre JP (2017). Overexpression of mitochondrial oxodicarboxylate carrier (ODC1) preserves oxidative phosphorylation in a yeast model of Barth syndrome. Dis Model Mech 10(4): 439-450. http://dx.doi.org/10.1242/dmm.027540