FIG. 5.

PP2A regulatory subunits and Msn2p translocation. A. PP2A scaffolding subunit Tpd3p is required for Msn2p translocation in response to rapamycin (rap), Tap42p depletion, and stress. Strains containing the full-length Msn2-GFP fusion protein were treated as described in the legend to Fig. 4 (23°C - glucose, 23°C medium lacking glucose) and visualized by epifluorescence and phase-contrast light microscopy. Strains AKY198 (wild type [WT]), AKY191 (tpd3Δ), AKY194 [tap42(Ts) TPD3], and AKY195 [tap42(Ts) tpd3Δ] are shown. B. PP2A regulatory subunit Cdc55p is required for Msn2p translocation in response to rapamycin and stress. Strains AKY163 (rts1Δ) and AKY185 (cdc55Δ) containing full-length Msn2-GFP and Msn2-myc₁₂ fusion proteins, respectively, were treated as described in the legend to Fig. 4 and visualized by epifluorescence and phase-contrast light microscopy. C. PP2A function and Msn2-dependent gene expression in response to Tap42p inactivation.β-Galactosidase (β-Gal) activities of the indicated CTT1-lacZ strains were measured during exponential growth at 23°C and 30 and 45 min (shown) after the shift to 36°C. Values shown are the mean of four measurements from two separate experiments. All standard deviations were less than 15%, with the exception of the 23°C measurement of the tap42-106 cdc55 strain, which was less than 35%. Strains AKY148 (TAP42 CDC55), AKY204 (TAP42 cdc55), AKY150 (tap42-106 CDC55), and AKY205 (tap42-106 cdc55) are shown. D. PP2A function and Msn2-dependent gene expression in response to osmotic shock. β-Galactosidase activities of the indicated CTT1-lacZ strains were measured during exponential growth in minimal medium and 30 min after the shift to minimal medium containing 1 M sorbitol (sorb). Values shown are the mean of four measurements from two separate experiments. All standard deviations were less than 15%. Strains AKY148 (TAP42 CDC55) and AKY205 (TAP42 cdc55) are shown.