Stress-Activated Degradation of Sphingolipids Regulates Mitochondrial Function and Cell Death in Yeast

Figure 6

Functional connection between the ERMES complex and hexadecenal-mediated cell death. (a) Colocalization study of Hfd1-GFP with the Mmm1-mCherry ERMES complex subunit. Cells were grown in synthetic galactose medium for the induced expression of the Mmm1-mCherry fusion. (b) Intracellular distribution of Hfd1p is affected in ERMES complex mutants. Hfd1-GFP was expressed in the indicated yeast strains and localized relative to MitoTracker-stained mitochondria. Cells were grown in synthetic glucose medium. (c) ERMES complex mutants are hypersensitive to hexadecenal. The growth efficiency upon external addition of hexadecenal (HD) was assayed as in Figure 3(a) in wild type and the indicated ERMES deletion mutants (upper panel). Quantitative colony assays are shown for the same strains in the lower panel. Cells from fresh overnight cultures in synthetic glucose medium were diluted to OD₆₀₀ 0.5 and then incubated with the indicated hexadecenal doses for 2 h. Colony-forming units were determined by plating the cells onto YPD agar medium. Data are presented as mean ± SD. Three biological replicates were analyzed. The colony number obtained for the wt upon control conditions was set to 100. Significant changes with respect to the wild type upon the same growth condition are marked. , (Student’s t-test).

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