title: Structural basis for recruitment of GRIP domain golgin-245 by small GTPase Arl1.
abstract: Recruitment of the GRIP domain golgins to the trans-Golgi network is mediated by Arl1, a member of the ARF/Arl small GTPase family, through interaction between their GRIP domains and Arl1-GTP. The crystal structure of Arl1-GTP in complex with the GRIP domain of golgin-245 shows that Arl1-GTP interacts with the GRIP domain predominantly in a hydrophobic manner, with the switch II region conferring the main recognition surface. The involvement of the switch and interswitch regions in the interaction between Arl1-GTP and GRIP accounts for the specificity of GRIP domain for Arl1-GTP. Mutations that abolished the Arl1-mediated Golgi localization of GRIP domain golgins have been mapped on the interface between Arl1-GTP and GRIP. Notably, the GRIP domain forms a homodimer in which each subunit interacts separately with one Arl1-GTP. Mutations disrupting the GRIP domain dimerization also abrogated its Golgi targeting, suggesting that the dimeric form of GRIP domain is a functional unit.
authors.affiliation: Laboratory of Macromolecular Structure, Institute of Molecular and Cell Biology, 30 Medical Drive, Singapore 117609.
authors.forename: Mousheng
authors.initials: M
authors.lastname: Wu
authors.forename: Lei
authors.initials: L
authors.lastname: Lu
authors.forename: Wanjin
authors.initials: W
authors.lastname: Hong
authors.forename: Haiwei
authors.initials: H
authors.lastname: Song
mesh_terms: D020727:ADP-Ribosylation Factors; D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D019281:Dimerization; D020558:GTP Phosphohydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: D001324:Autoantigens; C098772:GOLGA4 protein, human; D046911:Macromolecular Substances; D008565:Membrane Proteins; D011994:Recombinant Proteins; C097313:ADP-ribosylation factor related proteins; D020558:GTP Phosphohydrolases; D020727:ADP-Ribosylation Factors