Rab11-FIP3 and FIP4 interact with Arf6 and the Exocyst to control membrane traffic in cytokinesis

Abstract

The dual Rab11/Arf binding proteins, family of Rab11-interacting proteins FIP3 and FIP4 function in the delivery of recycling endosomes to the cleavage furrow and are, together with Rab11, essential for completion of abscission, the terminal step of cytokinesis. Here, we report that both FIP3 and FIP4 bind Arf6 in a nucleotide-dependent manner but exhibit differential affinities for Rab11 and Arf6. Both FIP3 and FIP4 can form ternary complexes with Rab11 and Arf6. Arf6 is localised to the furrow and midbody and we show that Arf6-GTP functions to localise FIP3 and FIP4 to midbodies during cytokinesis. Exo70p, a component of the Exocyst complex, also localises to the furrow of dividing cells and interacts with Arf6. We show that depletion of Exo70p leads to cytokinesis failure and an impairment of FIP3 and Rab11 localisation to the furrow and midbody. Moreover, Exo70p co-immunoprecipitates FIP3 and FIP4. Hence, we propose that FIP3 and FIP4 serve to couple Rab11-positive vesicle traffic from recycling endosomes to the cleavage furrow/midbody where they are tethered prior to fusion events via interactions with Arf6 and the Exocyst.

Cyclophilin function in Cancer; lessons from virus replication

“…Completion of cytokinesis in C. elegans requires Rab11 dependent membrane trafficking events to deliver new membrane to the furrow and for abscission, and depletion of Rab11 leads to cytokinesis defects including furrow regression and abnormal scission, confirming that endosomes provide membrane for cytokinesis [148]. Consistent with this, Rab11 and its binding partner FIP3 localise to the cleavage furrow during cell division in C. elegans and in mammalian cells [149,150].…”

“…Arf6 localises to the midbody during telophase and is responsible for the recruitment of Rab11/FIP3 and Rab11/FIP4 complexes [149]. Rab35, which is involved in the early endocytic recycling pathway, plays a crucial role during cytokinesis by mediating the localisation of phosphatidylinositol 4,5, bisphosphate (PIP2) lipid and the septin, SEPT2, to the growing cytokinetic bridge [151].…”

Cytokinesis in Animal Cells

“…FIP3 and the other Rab11 effector, FIP4 (both sharing homology with Nuf ), form a complex with Arf6 and depend on this protein for targeting to the central spindle ). Arf6 and FIP3/FIP4 also interact with Exo70, a subunit of the exocyst complex, a multiprotein complex that provides an essential role in tethering vesicles to plasma membrane before fusion (Prigent et al 2003;Fielding et al 2005). Consistent with a requirement for the exocyst complex in cytokinesis, knockdown of the exocyst subunit Sec5 results in the accumulation of v-SNARE-containing vesicles at the midbody in HeLa cells (Gromley et al 2005).…”

Arf GTPase-activating Protein ASAP1 Interacts with Rab11 Effector FIP3 and Regulates Pericentrosomal Localization of Transferrin Receptor–positive Recycling Endosome

“…FIP3 preferentially binds to Arf6 and Arf5 (Shin et al, 2001;Hickson et al, 2003;Fielding et al, 2005). We found FIP3 interaction stimulates ASAP1 GAP activity against Arf1, but not against Arf6.…”

“…FIP3 binds to two different classes of small GTP-binding proteins simultaneously, Rab11 and Arfs (Arf5 and Arf6; Shin et al, 1999;Prekeris, 2003;Fielding et al, 2005). Rab11 is known as a critical regulator for endocytic recycling pathway from recycling endosome to the plasma membrane and for trafficking at the trans-Golgi network (TGN) and functions in many cellular events including epithelial polarity, cell adhesion, and cytokinesis that depend on regulated membrane traffic (Zerial and McBride, 2001;van IJzendoorn, 2006).…”