Catalyzes the hydrolysis of the 5-position phosphate of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) and phosphatidylinositol-3,4,5-bisphosphate (PtdIns(3,4,5)P3), with the greatest catalytic activity towards PtdIns(4,5)P2. Able also to hydrolyze the 5-phosphate of inositol 1,4,5-trisphosphate and of inositol 1,3,4,5-tetrakisphosphate. Regulates traffic in the endosomal pathway by regulating the specific pool of phosphatidylinositol 4,5-bisphosphate that is associated with endosomes. Involved in primary cilia assembly. Acts as a regulator of phagocytosis, hydrolyzing PtdIns(4,5)P2 to promote phagosome closure, through attenuation of PI3K signaling. a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + H2O = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) + phosphate a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4,5-trisphosphate) + H2O = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4-bisphosphate) + phosphate 1D-myo-inositol 1,3,4,5-tetrakisphosphate + H2O = 1D-myo-inositol 1,3,4-trisphosphate + phosphate 1D-myo-inositol 1,4,5-trisphosphate + H2O = 1D-myo-inositol 1,4-bisphosphate + phosphate Interacts with APPL1, PHETA1/SES1 and PHETA2/SES2; APPL1-binding and PHETA1-binding are mutually exclusive. Interacts with clathrin heavy chain. Interacts with several Rab GTPases, at least RAB1B, RAB5A, RAB6A and RAB8A; these interactions may play a dual role in targeting OCRL to the specific membranes and stimulating the phosphatase activity. Interaction with RAB8A modulates OCRL recruitment to cilia (By similarity). Interacts with RAB31 (PubMed:19795375). Interacts with INPP5F (By similarity). Also found on macropinosomes. Detected in brain oligodendrocytes (at protein level). Detected in brain oligodendrocytes. The ASH (ASPM-SPD2-Hydin) and RhoGAP (Rho GTPase activating) domains form a single folding module. The ASH domain has an immunoglobulin-like fold, the Rho-GAP domain lacks the catalytic arginine and is catalytically inactive. The ASH-RhoGAP module regulates the majority of the protein-protein interactions currently described. The ASH domain mediates association with membrane-targeting Rab GTPases. The Rho-GAP domain interacts with the endocytic adapter APPL1, which is then displaced by PHETA1 and PHETA2 as endosomes mature (By similarity). Belongs to the inositol 1,4,5-trisphosphate 5-phosphatase type II family.