PP2A is required for Atg1 activation after the inactivation of TORC1.

<p>(A) Cells of strains SCU893 (wild type) and SCU2422 (<i>pph21</i>Δ <i>pph22</i>Δ) were treated with rapamycin for 15 min. Whole cell extracts were subjected to western blotting using an anti-Atg1 antibody. Phosphorylated Atg1 was measured using ImageJ software, and quantified by calculating the ratio of phosphorylated Atg1 versus dephosphorylated Atg1. Relative values normalized against the value in control cells are shown. P-Atg1, phosphorylated Atg1. (B) Cells of strains SCU893 (wild type) and SCU4225 (<i>cdc55Δ rts1</i>Δ) were treated with rapamycin for 15 min. Whole cell extracts were subjected to western blotting as for panel (A).