Fig. 1

PI4P distribution is regulated by growth conditions. a Schematic representation of kinases and phosphatases involved in PI4P and PI(4,5)P₂ metabolism. Heat shock elicits PI4P- and PI(4,5)P₂-mediated signaling responses including regulated exocytosis and endocytosis. b Schematic representation of the method used to measure PM GFP-P4C fluorescence intensities at 26 °C and after 42 °C heat shock. Briefly, line scans were applied through both daughter and mother cells using Fiji, and the peak values corresponding to the GFP-P4C fluorescence intensity at the PM in the daughter (Fd) and mother cell (Fm) were recorded to calculate Fd/Fm ratios. c Quantitation of GFP-P4C fluorescence at the plasma membrane (PM) of daughter (Fd) and mother (Fm) cells at 26 °C and after a 10 min 42 °C heat shock. Graph shows the Fd and Fm mean values of individual cells. Total number of cells analyzed in three independent experiments: 26 °C, n = 40, 10 min 42 °C, n = 45. Error bars show standard deviations. The changes in Fd and Fm after heat shock are statistically significant (t test, ****p < 0.0001, ***p = 0.0002). d Quantitation of GFP-P4C fluorescence at the plasma membrane (PM) of daughter (Fd) and mother (Fm) cells at 26 °C and after a 10 min heat shock as described in c. Graph shows the Fd/Fm ratio of individual cells. Total number of cells analyzed in three independent experiments: 26 °C, n = 40, 10 min 42 °C, n = 45. Error bars show standard deviations. The decrease in the Fd/Fm ratio after heat shock is statistically significant (t test, ****p < 0.0001)