Inositol polyphosphate 5-phosphatase (OCRL1) converts phosphatidylinositol 4,5-biphosphate to phosphatidylinositol 4-phosphate. The enzyme also converts inositol 1,4,5-trisphosphate to inositol 1,4-bisphosphate and inositol 1,3,4,5-tetrakisphosphate to inositol 1,3,4-trisphosphate. The enzyme is involved in lysosomal membrane trafficking by regulating the specific pool of phosphatidylinositol 4,5-bisphosphate that is associated with lysosomes. Defects in OCRL1 are the cause of Lowe syndrome, a multisystem disorder affecting eyes, nervous system and kidney, and Dent disease type 2, a renal disease.The synthetic peptide used to raise the antibody Cat. No. 200177 is selected from a sequence within the C-term region of human OCRL1. For blocking experiments, a 10 to 100 fold molar excess to antibody is recommended.