Figure 7
C. albicans Sap6 deletion results in defective growth in low zinc medium and reduced intracellular zinc accumulation. (A) C. albicans CAI4 and Δzap1, Δpra1, Δzrt1, Δsap5, Δsap6, Δsap6/SAP6 and SAP6O/E cells were inoculated into Low Zinc Medium (LZM) with initial OD600 = 0.01, grown for 24 h at 30 °C, and growth measured at OD600. C. albicans Δzap1 cells had the largest reduction in growth followed by Δzrt1 and Δsap6. Data are averages of three independent experiments. (B) CAI4, Δsap6 and Δsap6/SAP6 were grown overnight in LZM, germinated, fixed with paraformaldehyde, and stained with Zinquin (25 µM). Accumulation of intracellular zinc was measured by relative intensity of Zinquin staining. C. albicans Δsap6 strain had decreased Zinquin compared to CAI4 which was reversed upon Δsap6/SAP6 complementation. (C) Cells were grown overnight in LZM, germinated in the presence of 100 µM ZnCl2 (black bars) or without added zinc (white bars), and relative intensity of Zinquin fluorescence in hyphal cells measured. C. albicans Δzap1, Δpra1, Δzrt1 and Δsap6 all had significantly (P < 0.001) lower Zinquin staining with or without added zinc compared to CAI4. In contrast, SAP6 O/E strain had a significant (P < 0.05) increase in Zinquin staining only in low zinc conditions, while the Sap6 revertant (Δsap6/SAP6) and Δsap5 cells were not significantly different than WT cells. Values are mean ± SD of three independent replicates.
