The unexpected role of Drosophila OCRL during cytokinesis.

Inositides are intrinsic components of cell membranes that regulate a wide variety of cellular functions. PtdIns(4,5)P(2,) one of the most abundant phosphoinositides, is restricted at the plasma membrane where it regulates numerous functions including cell division. We have recently established that the Drosophila inositol 5-phosphatase, dOCRL, is essential for cytokinesis, the last step of cell division (Ben El Kadhi et al. 2011).(8) We demonstrated that dOCRL is required for the dephosphorylation of PtdIns(4,5)P(2) at the surface of endosomes, resulting in the restriction of this phosphoinositide to the cell cortex during cytokinesis. dOCRL is the Drosophila ortholog of human OCRL1, a PtdIns(4,5)P(2) phosphatase mutated in the X-linked disorder oculocerebrorenal Lowe syndrome. Here, we discuss the relevance of our findings with reference to the role of human OCRL1 in non-pathological and pathological conditions.