Dur31 contributes to cell wall integrity.

<p>Drop test analysis with serial dilutions of <i>C. albicans</i> wild type (Wt), <i>dur31</i>Δ/Δ mutant and <i>dur31</i>Δ/Δ::<i>DUR31</i> complemented mutant strain ranging from 10⁶ to 10¹ cells (left to right) on agar containing or exposed to different stressors. (A) Growth of the <i>dur31</i>Δ/Δ mutant on SD agar under thermal stress (42°C), cell wall stress (450 µg ml⁻¹ Congo red) and heavy metal stress (0.75 mM silver nitrate). Plates subjected to thermal stress were incubated for 4–5 days and cells grown under cell wall or reductive stress for 2–3 days at 37°C. (B) The <i>dur31</i>Δ/Δ mutant displays moderately enhanced tolerance towards UV stress. Serial ten-fold dilutions were prepared and spotted onto YPD agar plates. Cells were then exposed to the indicated intensities of UV-C light and subsequently incubated at 37°C for 2 days. (C) Western blot analysis for identification of phosphorylated Mkc1. <i>dur31</i>Δ/Δ has increased levels of phosphorylated Mkc1 upon treatment with the cell wall attacking agent Congo red. The wild type (Wt), <i>dur31</i>Δ/Δ mutant, <i>dur31</i>Δ/Δ::<i>DUR31</i> complemented strain and <i>mkc1</i>Δ/Δ mutant were grown under non-stress conditions (control) or conditions of cell wall stress (+Congo red) for 4 hours at 30°C. Protein extracts were blotted and probed for phosphorylated Mkc1 (Mkc1-P). Blots were then stripped and re-probed for α-tubulin (loading control). The <i>mkc1</i>Δ/Δ mutant was included as a negative control for the Mkc1-P detection.