FIGURE 6.

The Sit4 protein phosphatase is a SL-downstream target in regulating tau phosphorylation. (A) The tau isoforms from pYX212-Tau2N/4R transformants of the BY4741 wild-type (wt), pho85, lcb3, lcb4, and lcb5 mutant strains grown in SCD-Ura medium were analyzed by Western blot as described in Figure 1C. Data represent the mean value (±SD) of three independent experiments. Statistically significant differences (p < 0.05) between mutant strains and the wild-type control strain are indicated (*). (B) Proteins extracts from logarithmic-grown cultures of pYX212-Tau2N/4R transformants of the CEN.PK2-1C wild-type (wt) strain, sit4, sit4 lcb4, and sit4 lcb5 were analyzed as in (A). (C) Cells of the same strains were examined for growth in YPD lacking or containing 0.068 μM aureobasidin A (YPD+AbA). Overnight YPD-grown cultures were adjusted to Abs₆₀₀ ∼0.5, diluted (1–10^–3), spotted (3 μl) onto the mentioned media, and incubated at 30°C for 2–5 days. A representative experiment is shown.