Figure 6
Low concentrations of H 2 O 2 upregulate Tdh1p and high concentrations downregulate Tdh2p and Tdh3p protein levels in stationary-phase S. cerevisiae cells. Cells were treated with the steady-state H2O2 concentrations indicated for 60 min. (A) Representative protein loading and immunoblot analysis of Tdh2p/Tdh3p (n = 6) and signal intensity quantification expressed as the mean ± standard deviation in arbitrary units (a.u.) relative to control. Mouse anti-GAPDH, which only reacts with Tdh2p and Tdh3p, was used for Tdh2p/Tdh3p identification (see Figure 3). (B) Representative two-dimensional analysis of Tdh1p, Tdh2p and Tdh3p (only the region with the three GAPDH isoenzymes is shown, n≥4) in stationary-phase cells with immunodetection made by Western blot using rabbit anti-GAPDH as described in materials and methods; signal intensity quantification of GAPDH levels normalized to Zwf1p, which was used as internal control, and expressed as the mean ± standard deviation in arbitrary units (a.u.) relative to control is also shown. *P < 0.05 vs control.