Alternative titles; symbolsKIAA1821HGNC Approved Gene Symbol: RAB11FIP4Cytogenetic location: 17q11.2 Genomic coordinates (GRCh38): 17:31,391,674-31,538,210 (...
Alternative titles; symbols
HGNC Approved Gene Symbol: RAB11FIP4
Cytogenetic location: 17q11.2 Genomic coordinates (GRCh38): 17:31,391,674-31,538,210 (from NCBI)
Proteins of the large Rab GTPase family (see RAB1A; 179508) have regulatory roles in the formation, targeting, and fusion of intracellular transport vesicles. RAB11FIP4 is one of many proteins that interact with and regulate Rab GTPases (Hales et al., 2001).
▼ Cloning and Expression
By sequencing clones obtained from a size-fractionated fetal brain cDNA library, Nagase et al. (2001) cloned a partial RAB11FIP4 cDNA, which they designated KIAA1821. RT-PCR ELISA detected strong expression in adult brain, moderate expression in fetal brain, kidney and pancreas, with strong to moderate expression in specific adult brain regions examined.
By database analysis using mouse Rab11fip4, Wallace et al. (2002) identified RAB11FIP4. The deduced 637-amino acid protein contains an N-terminal EF-hand domain, a C-terminal coiled-coil domain, ERM motif, and Rab11-binding domain. RAB11FIP4 shares 92% homology with its mouse ortholog. Immunofluorescence studies colocalized RAB11FIP4 with RAB11A (605570) to the endosomal recycling compartment (ERC) and to endosomal membranes.
▼ Gene Function
By yeast 2-hybrid and Far Western analysis Wallace et al. (2002) demonstrated that RAB11FIP4 interacted specifically with active RAB11 (see RAB11A; 605570), demonstrating no interaction with an S25N-mutant RAB11 or with a constitutively active RAB11 mutant. RAB11FIP4 showed no interaction with other RAB family members. RAB11FIP4 formed homodimers and also bound RAB11FIP2 (608599), RAB11FIP3 (608738), and RIP11 (RAB11FIP5; 605536), but did not bind RAB11FIP1 (608737). Using the RAB11FIP4 C-terminal region, Wallace et al. (2002) showed that RAB11FIP4 did not inhibit transferrin (190000) recycling.
Fielding et al. (2005) used immunofluorescence studies to colocalize RAB11FIP4 and ARF6 (600464) to the furrow and midbody during cytokinesis, and they demonstrated that this RAB11FIP4 localization was ARF6-dependent. They suggested that RAB11FIP4 plays a role in vesicle docking at the midbody. In vitro binding analysis showed the nucleotide-dependent interaction of RAB11FIP4 with ARF6 GTPase with weaker affinity for RAB11 and ARF5 (103188). RAB11FIP4 coimmunoprecipitated with exocyst complex protein Exo70p (EXOC7; 608163), RAB11FIP3, and RAB11. They concluded that RAB11FIP4 mediates vesicle docking during cytokinesis.