Genome-Wide Analysis Reveals the Vacuolar pH-Stat of Saccharomyces cerevisiae (original) (raw)
Figure 4
Transporter dysfunction in _vps36_Δ cells.
(a) Nhx1 is mislocalized in _vps36_Δ cells. Micrographs show the location of Nhx1-GFP in nhx1Δ or _vps36_Δ cells transformed with the 2 µ plasmid pRin82 containing NHX1:GFP behind its endogenous promoter. Bar, 2 µm. The number of Nhx1-GFP stained puncta per cell was quantified; >100 cells were analyzed for each strain. (b) _vps36_Δ phenocopies _nhx1_Δ. Growth of wild type BY4742 (wt), _nhx1_Δ or _vps36_Δ cultures was measured after 19 hrs at 30°C under control conditions (APG, pH 4.0), acid stress (pH 2.7), or in the presence of 10 µg/ml hygromycin B (Hygro B), 1.5 M KCl or 1.5 M NaCl. Bars represent mean +/− S.E.M. (c) The pH homeostasis defect in _nhx1_Δ is downstream of Vps36 function. Micrographs show the cellular location of Ste3-GFP in wild type BY4742 (wt), _nhx1_Δ or _vps36_Δ cells grown in APG pH 4.0 medium at 30°C with or without methylamine (MA, 10 mM) treatment. Note that pH amelioration fails to correct trafficking dysfunction in _vps36_Δ cells. Bar, 2 µm.