INPP5B and oculocerebrorenal syndrome: Dephosphorylation of PI(4,5)P2 and therefore membrane scission of the prevacuole is realised via the recruitment of Rab5-positive vesicles and the Rab5 effector phosphatases OCRL (oculocerebrorenal syndrome of Lowe protein) and INPP5B (inositol polyphosphate-5-phosphatase B).