HPLC analysis of deacylated phosphoinositides from HEK 293 cells and budding yeast. Radiolabeled lipids from HEK293 cells overexpressing wild-type or mutant (C375S) myotubularin, and wild-type (GYC121) or myotubularin homolog null mutant (ΔYJR110w) budding yeast strains, were deacylated and separated by anion exchange chromatography as described in Materials and Methods. (a) Elution profile of radiolabeled gPIPs from 293 cells overexpressing wild-type (WT) myotubularin. (b) Elution profile of radiolabeled gPIPs from 293 cells overexpressing a catalytically inactive myotubularin mutant (C375S). (c) Elution profile of radiolabeled gPIPs from wild-type yeast. (d) Elution profile of radiolabeled gPIPs from ΔYJR110w yeast. The elution positions of gPI(3)P, gPI(4)P, and gPI(4,5)P2 reference standards are indicated by arrows. Sample loadings represent equivalent total cellular protein and total radiolabeled phosphoinositides. Chromatographs are representative of four independent experiments.