Copper permeabilizes plasma membranes of <i>C</i>. <i>albicans</i> copper-sensitive strains with morphogenesis defects.

2019-01-11T18:38:04Z (GMT) by Lois M. Douglas James B. Konopka
<p>(A) Log phase <i>sur7Δ</i> cells were incubated in water containing the indicated concentrations of CuSO<sub>4</sub> for 2 hr at 37°C and then stained with SYTOX Green to assess the integrity of the plasma membrane. The <i>sur7Δ</i> mutant displayed increased permeabilization of the plasma membrane with increased copper concentration compared to the wild type and <i>Sur7</i> complemented strains. (B) Time course assay in which log phase <i>sur7Δ</i> cells were incubated in 10 μM CuSO<sub>4</sub> for the indicated time at 37°C and then stained with SYTOX Green. The <i>sur7Δ</i> cells suffered greater membrane damage as early as 30 min after addition of copper.(C) Log phase cells of the morphogenesis mutants <i>rvs161Δ</i>, <i>rvs167Δ</i>, and <i>arp2Δ arp3Δ</i> strains were incubated in 10 μM CuSO<sub>4</sub> for 2 hr at 37°C and then stained with SYTOX Green. All mutants demonstrated increased staining, indicative of membrane permeabilization. (D) Log phase cells of known copper mutants were incubated in 10 μM CuSO<sub>4</sub> for 2 hr at 37°C and then stained with SYTOX Green. The <i>crp1Δ</i>, <i>crp1Δ cup1Δ</i>, and <i>cup2Δ</i> strains all showed significantly less staining than the <i>sur7Δ</i> strain, indicating a low level of membrane permeabilization caused by CuSO<sub>4</sub>. Error bars indicate SD. ****, P<0.001. ***, P<0.01. **, P<0.01, *, P<0.05 by two-way ANOVA in comparison to the corresponding wild type values. The results represent the average of three independent assays (panels A, C, D) or six independent assays (Panel B) carried out on different days. Strains used included DIC185, <i>sur7Δ</i> (YJA11), <i>crp1Δ</i> (KC16), <i>cup1Δ crp1Δ</i> (KC25), and <i>cup2Δ</i> (YLD117-1).</p>