Model for Sac2 function during endosomal recycling. The recycling process is dependent on the proper control of PIs. Initial stage of endocytosis requires the hydrolysis of PI(4,5)P₂ to PI(4)P via PI 5-phosphatases, such as OCRL. Sac2 is then recruited to endocytic intermediates to hydrolyze PI(4)P to phosphatidylinositol, which is a substrate for Vps34 to generate PI(3)P. The spatiotemporal conversion from PI(4,5)P₂- to PI(3)P-enriched endosome is essential for endosomal maturation and subsequent recycling events.