title: VARP is recruited on to endosomes by direct interaction with retromer, where together they function in export to the cell surface.
abstract: VARP is a Rab32/38 effector that also binds to the endosomal/lysosomal R-SNARE VAMP7. VARP binding regulates VAMP7 participation in SNARE complex formation and can therefore influence VAMP7-mediated membrane fusion events. Mutant versions of VARP that cannot bind Rab32:GTP, designed on the basis of the VARP ankyrin repeat/Rab32:GTP complex structure described here, unexpectedly retain endosomal localization, showing that VARP recruitment is not dependent on Rab32 binding. We show that recruitment of VARP to the endosomal membrane is mediated by its direct interaction with VPS29, a subunit of the retromer complex, which is involved in trafficking from endosomes to the TGN and the cell surface. Transport of GLUT1 from endosomes to the cell surface requires VARP, VPS29, and VAMP7 and depends on the direct interaction between VPS29 and VARP. Finally, we propose that endocytic cycling of VAMP7 depends on its interaction with VARP and, consequently, also on retromer.
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Geoffrey G
authors.initials: GG
authors.lastname: Hesketh
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Pérez-Dorado
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Lauren P
authors.initials: LP
authors.lastname: Jackson
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Lena
authors.initials: L
authors.lastname: Wartosch
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK.
authors.forename: Ingmar B
authors.initials: IB
authors.lastname: Schäfer
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Sally R
authors.initials: SR
authors.lastname: Gray
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Airlie J
authors.initials: AJ
authors.lastname: McCoy
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: Oliver B
authors.initials: OB
authors.lastname: Zeldin
authors.affiliation: Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: Elspeth F
authors.initials: EF
authors.lastname: Garman
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Harbour
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK.
authors.forename: Philip R
authors.initials: PR
authors.lastname: Evans
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK. Electronic address: mnjs100@cam.ac.uk.
authors.forename: Matthew N J
authors.initials: MNJ
authors.lastname: Seaman
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK. Electronic address: jpl10@cam.ac.uk.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Luzio
authors.affiliation: Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK. Electronic address: djo30@cam.ac.uk.
authors.forename: David J
authors.initials: DJ
authors.lastname: Owen
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism*; D018360:Crystallography, X-Ray; D011992:Endosomes / Q000502:physiology*; D051272:Glucose Transporter Type 1 / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D055503:Protein Multimerization; D021381:Protein Transport; D050683:R-SNARE Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000378:metabolism*
chemical_list: C491304:ANKRD1 protein, human; C529611:ANKRD27 protein, human; D051272:Glucose Transporter Type 1; D020662:Guanine Nucleotide Exchange Factors; D009124:Muscle Proteins; D009687:Nuclear Proteins; D050683:R-SNARE Proteins; D012097:Repressor Proteins; C495677:SLC2A1 protein, human; C121241:VAMP7 protein, human; C419572:VPS29 protein, human; D033921:Vesicular Transport Proteins; D006160:Guanosine Triphosphate; C466094:Rab32 protein, human; D020691:rab GTP-Binding Proteins