The FIP3-Rab11 protein complex regulates recycling endosome targeting to the cleavage furrow during late cytokinesis.

An integral part of cell division is the separation of daughter cells via cytokinesis. There is now good evidence that the completion of cytokinesis requires coordinated membrane trafficking to deliver new membrane to the tip of the furrow and to complete the abscission. Here we have examined membrane traffic in cytokinesis and describe several novel observations. First, we show that Rab11- and FIP3-containing recycling endosomes accumulate near the cleavage furrow and are required for successful completion of cytokinesis. Second, we demonstrate that the Rab11-FIP3 protein complex is intimately involved in the delivery of endosomes to the cleavage furrow. Significantly, although FIP3 recruitment to endosomes is Rab11 dependent, we find that the targeting of FIP3 to the midbody is independent of Rab11. Third, we show that the Rab11-FIP3 complex is required for a late stage of cytokinesis, possibly abscission. Finally, we demonstrate that localization of FIP3 is subject to substantial spatial and temporal regulation. These data provide the first detailed analysis of recycling endosomes in cell division and provide a new model for membrane traffic to the furrow. We propose that the dynamic Rab11-FIP3 interaction controls the delivery, targeting, and fusion of recycling endosomes with furrow during late cytokinesis and abscission.