title: Arfophilins are dual Arf/Rab 11 binding proteins that regulate recycling endosome distribution and are related to Drosophila nuclear fallout.
abstract: Arfophilin is an ADP ribosylation factor (Arf) binding protein of unknown function. It is identical to the Rab11 binding protein eferin/Rab11-FIP3, and we show it binds both Arf5 and Rab11. We describe a related protein, arfophilin-2, that interacts with Arf5 in a nucleotide-dependent manner, but not Arf1, 4, or 6 and also binds Rab11. Arfophilin-2 localized to a perinuclear compartment, the centrosomal area, and focal adhesions. The localization of arfophilin-2 to the perinuclear compartment was selectively blocked by overexpression of Arf5-T31N. In contrast, a green fluorescent protein-arfophilin-2 chimera or arfophilin-2 deletions were localized around the centrosome in a region that was also enriched for transferrin receptors and Rab11 but not early endosome markers, suggesting that the distribution of the endosomal recycling compartment was altered. The arfophilins belong to a conserved family that includes Drosophila melanogaster nuclear fallout, a centrosomal protein required for cellularization. Expression of green fluorescent protein-nuclear fallout in HeLa cells resulted in a similar phenotype, indicative of functional homology and thus implicating the arfophilins in mitosis/cytokinesis. We suggest that the novel dual GTPase-binding capacity of the arfophilins could serve as an interface of signals from Rab and Arf GTPases to regulate membrane traffic and integrate distinct signals in the late endosomal recycling compartment.
authors.affiliation: The Henry Wellcome Laboratory of Cell Biology, Division of Biochemistry and Molecular Biology, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland.
authors.forename: Gilles R X
authors.initials: GR
authors.lastname: Hickson
authors.forename: Johanne
authors.initials: J
authors.lastname: Matheson
authors.forename: Blake
authors.initials: B
authors.lastname: Riggs
authors.forename: Valerie H
authors.initials: VH
authors.lastname: Maier
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Fielding
authors.forename: Rytis
authors.initials: R
authors.lastname: Prekeris
authors.forename: William
authors.initials: W
authors.lastname: Sullivan
authors.forename: Francis A
authors.initials: FA
authors.lastname: Barr
authors.forename: Gwyn W
authors.initials: GW
authors.lastname: Gould
mesh_terms: D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D016466:CHO Cells; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018385:Centrosome / Q000378:metabolism; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000235:genetics; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017385:Sequence Homology; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
chemical_list: D020727:ADP-Ribosylation Factors; D002352:Carrier Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C439063:RAB11FIP3 protein, human; C403131:arfophilin; C111662:nuf protein, Drosophila