RAB11 Family Interacting Protein 1 (RAB11FIP1)

Proteins of the large Rab GTPase family have regulatory roles in the formation, targeting, and fusion of intracellular transport vesicles. RAB11FIP1 is one of many proteins that interact with and regulate Rab GTPases. The deduced protein contains a C-terminal 18-amino acid amphipathic helix responsible for the interaction with Rab11a. Rabbit and human RAB11FIP1 share 99% amino acid identity. Western blot analysis of rabbit gastric mucosa microsomes detected Rab11fip1 at an apparent molecular mass of 89 kD. Immunofluorescence microscopy of HeLa cells demonstrated that endogenous RAB11FIP1 colocalized with RAB11FIP2, RIP11 , and RAB11A. Confocal immunofluorescent microscopy indicated colocalization in the apical region of canine kidney cells.