A phosphatase deletion screen identifies Ppg1 as a regulator of storage carbohydrate metabolism.

A) Schematic depicting growth kinetics of S. cerevisiae cells in glucose-replete conditions and varying metabolic states during different phases of growth. S cerevisiae cells rewire their metabolism after diauxic adaptation. B) Schematic describing the screen designed to identify protein phosphatases that regulate post-diauxic carbon metabolism. For the screen, phosphatase knockouts were started in a glucose-replete medium, and trehalose accumulation was measured after 24hrs of growth. Also, see S1A Fig for the table of phosphatase mutants used in this study. C) Identifying phosphatase knockouts with altered trehalose amounts. The heat map shows relative trehalose amounts in phosphatase knockouts compared to wild-type cells. Trehalose accumulation was measured after 24hrs of growth in YPD medium. The mean trehalose levels were from 2 biological replicates. Also, see S1A Fig for steady-state trehalose amounts. D) Effect of loss of phosphatase activity of Ppg1 on the accumulation of storage carbohydrates in post-diauxic phase. A catalytically inactive mutant of Ppg1-Ppg1^H111N was generated. WT, ppg1Δ, and Ppg1^H111N cells were grown in a glucose-replete medium and trehalose and glycogen were measured after 24hrs. Data represented as a mean ± SD (n = 3). *P < 0.05, **P < 0.01, and ***P< 0.001; n.s., non-significant difference, calculated using unpaired Student’s t tests. Also see S1B, S1D and S1E Fig.