FIG 5.

Proteasome inhibition induces morphogenesis in diverse fungal species. (A) Pharmacological inhibition of the proteasome with bortezomib induces morphogenesis in C. albicans, C. dubliniensis, C. tropicalis, C. krusei, and C. parapsilosis. Hsp90 inhibition with geldanamycin induces morphogenesis in all Candida species tested. Strains were grown in the absence or presence of the indicated concentrations of drug at 30°C for 24 h under static conditions before imaging. Scale bar, 10 μm. (B) Dose-response assays with geldanamycin or bortezomib. Cells were inoculated in YPD medium with 2-fold dilutions of geldanamycin or bortezomib. After incubation at 30°C for 24 h under static conditions, growth was measured by the OD₆₀₀. Data shown are the average of two technical replicates. Data are quantitatively displayed with color using Treeview (as indicated by the legend). (C) Protein ubiquitination in response to inhibition of the proteasome. Cells were grown for 7 h in the absence or presence of bortezomib (treated with the same concentrations as described for panel A) at 30°C, with shaking. Protein extracts were prepared and analyzed by western blotting. Immunoblots with an anti-ubiquitin antibody (Ub) and Ponceau as a loading control are shown.