Interactions of myosin vb with rab11 family members and cargoes traversing the plasma membrane recycling system.

Myosin Vb interacts with Rab11 family members and is the major motor protein identified in association with plasma membrane recycling systems in nonpolarized and polarized cells. Using yeast two-hybrid binary screens, we demonstrated that dominant active Rab25S21V fails to interact with myosin Vb, but does interact with Rab11-FIP2. Transfection of DsRed2-myosin Vb tail in MDCK cell lines stably transfected with wild-type or dominant active forms of Rab11a or Rab25 demonstrated that the distribution of Rab25S21V is only partially altered by expression of the myosin Vb tail. Finally, we demonstrate EGF-dependent sequestration of internalized EGF receptor by EGFP-myosin Vb in A431 cells. Expression of myosin Vb tail represents a powerful provocative test for the trafficking of cargoes through Rab11-containing plasma membrane recycling systems.