Fig. 1.

Oxidative stress and carbon source stress regulate C. glabrata catalase CgCTA1. A. To measure catalase activity upon glucose depletion, cells were grown to log phase in YPD and shifted to medium with 2% or 0.1% glucose and grown for 4 h. Catalase activity was determined as described in Experimental procedures. B. Cells were incubated in YPD with 0.4 mM H₂O₂ for 45 min. Crude cell extracts were prepared and then assayed for catalase activity. C. Northern blot analysis of CgCTA1 mRNA levels from wild type, ARCg cta1Δ mutant and complemented mutant strain was performed under stress conditions (glucose starvation, 0.4 mM H₂O₂). Samples were taken at the indicated time points. CgACT1 mRNA levels were used as loading control. mRNA levels were visualized by hybridization of radioactive probes and autoradiography. The pCgC–GFP–CgCTA1 construct with GFP inserted at the N-terminus is illustrated. D. C. glabrata ARCg cta1Δ mutant complemented with pGFP–CgCTA1, pCgCTA1 or an empty plasmid was grown in synthetic medium to log phase, adjusted to 10⁵ cells ml⁻¹ and exposed to indicated doses of hydrogen peroxide. Optical density after 24 h of incubation at 37°C is indicated.