Figure 4.

Analysis of the TSA1 point mutations. (A) Sensitivity of the TSA1 point mutations to tBOOH. Cultures of the tsa1Δ strain containing Ycplac111, WT.TSA1, TSA1^AS, TSA1^LT, or TSA1^AS/LT were grown to midlog phase, and 10-fold serial dilutions were spotted onto SD medium containing various concentrations of tBOOH. (B) H₂O₂-induced expression of TRX2. Northern blot analysis of RNA isolated from midlog-phase cultures either untreated (lanes 1, 3, 5, 7, and 9) or treated with 0.1 mM H₂O₂ for 20 min (lanes 2, 4, 6, 8, and 10) with the use of probes specific for the TRX2 and ACT1 transcripts. The tsa1Δ strain contained Ycplac111 (lanes 1 and 2), WT.TSA1 (lanes 3 and 4), TSA1^AS (lanes 5 and 6), TSA1^LT (lanes 7 and 8), or TSA1^AS/LT (lanes 9 and 10). The panel below the Northern blots shows quantitation of the TRX2 transcript level relative to the ACT1 transcript.