At the Golgi membrane, phosphatidylinositol 4-phosphate (PI4P) inositol polyphosphate 5-phosphatase OCRL-1 (OCRL) (Choudhury et al. 2009, Suchy et al. 1995, Zhang et al. 1995) and 72 kDa inositol polyphosphate 5-phosphatase (INPP5E) (Bilas et al. 2009) dephosphorylate phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) to form phosphatidylinositol 4-phosphate (PI4P). INPP5E is located in the Golgi membrane, mediated by its N-terminal proline-rich domain (Kong et al. 2000).