Back to article: Ydj1 governs fungal morphogenesis and stress response, and facilitates mitochondrial protein import via Mas1 and Mas2
FIGURE 7: Mas1, Mas2 and Ydj1 are important for mitochondrial morphology and function. (A) The wild-type, tetO-MAS1/mas1Δ and tetO-MAS2/mas2Δ strains were grown in YPD in the ab-sence (- Dox) or presence (+ Dox) of 20 μg/mL doxycycline for 24 hours, and then subcultured in the same conditions for an additional 4 hours to deplete MAS1 and MAS2. Cells were stained with MitoTracker Red dye (mitochondria) for one hour, and examined by confocal microscopy. Representative images are shown. Scale bar indicates 5 μm. (B) Ydj1 is required for normal mitochon-drial morphology at high temperatures. The ydj1Δ/ydj1Δ mutant was grown in YPD for 16 hours at 30°C, and then dilut-ed 10 times in fresh YPD medium and grown for a further 6 hours at 30°C or 37°C. Samples were stained with 100 nM MitoTracker Red for 1 hour and examined by confocal microscopy. Representative images are shown. The scale bars indicate 5 μm. (C) Ydj1 is re-quired for import of the artificial substrate Su9-GFP under elevated temperatures. Whole cell extract (WCE) and gradient-purified mitochondria were obtained from wild-type and ydj1Δ/ydj1Δ cells harboring tetO-Su9-GFP, which were grown at 30°C or 37°C for 6 hours. The blots demonstrate significant accumulation of the Su9-GFP precursor form in a ydj1Δ/ydj1Δ mu-tant grown at elevated temperatures. The anti-Hog1 and anti-Aac2 antibody staining was used as a marker of mitochondrial preparation purity. Ponceau S staining was used as control for protein loading. (D) Growth kinetics of the wild-type (SN95) laboratory strain of C. albicans and the ydj1Δ/ydj1Δ mutant were measured in YPD or YPG medium at 30°C with orbital shaking, with measurements taken every 15 minutes for 48 hours. P ≤ 0.05, Two-Way ANOVA, Sidak’s Multiple Comparisons Test.