FIG 4.

PP6 is the primary phosphatase that keeps AMPK inactive in high glucose. (A) Ppe1 is required for dephosphorylation of Ssp2-pT189 under high-glucose conditions. Phosphatase mutant strains were grown in high (2%) or low (0.1%) glucose, and whole-cell lysates were blotted with anti-Ssp2-pT189 antibody. The asterisks denote background bands, and the arrowheads mark Ssp2-pT189 bands. (B) Effects of the indicated concentrations of okadaic acid (OA) on Ssp2-pT189 in ppe1⁺ and ppe1Δ strains. Whole-cell extracts were blotted.