title: Multilayer interactions determine the Golgi localization of GRIP golgins.
abstract: Golgin-97, RanBP2alpha, Imh1p and p230/golgin-245 (GRIP) domain golgins are targeted to the Golgi membrane through their GRIP domains. By analyzing more than 30 mutants of golgin-97 and golgin-245 GRIP domains for their properties of dimerization, interaction with ARF like protein 1 (Arl1)-GTP and Golgi targeting, we found hierarchically organized three-tier interactions governing the Golgi targeting of GRIP domain golgins. GRIP domain self-dimerization is necessary for bivalent interaction with Arl1-GTP. Unexpectedly, however, these two interactions are not sufficient for Golgi targeting, as a third group of residues, including positive-charged arginine between alpha1 and alpha2 and hydrophobic residues C-terminal to the GRIP domain, turn out to be essential. Surface plasmon resonance analysis indicates that GRIP domain interacts directly with membrane lipid, partially through the third group of residues such as W744 of golgin-97. This third tier of interaction with the membrane could be mediated by non-specific hydrophobic and electrostatic forces.
authors.affiliation: Membrane Biology Laboratory, Institute of Molecular and Cell Biology, Proteos Building, 61 Biopolis Drive, Singapore.
authors.forename: Lei
authors.initials: L
authors.lastname: Lu
authors.forename: Guihua
authors.initials: G
authors.lastname: Tai
authors.forename: Mousheng
authors.initials: M
authors.lastname: Wu
authors.forename: Haiwei
authors.initials: H
authors.lastname: Song
authors.forename: Wanjin
authors.initials: W
authors.lastname: Hong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D006056:Golgi Apparatus / Q000378:metabolism / Q000648:ultrastructure; D000077614:Golgi Matrix Proteins; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: D001324:Autoantigens; C098772:GOLGA4 protein, human; D000077614:Golgi Matrix Proteins; C450721:Golgi complex autoantigen, 97-kDa; C117417:IMH1 protein, S cerevisiae; D008055:Lipids; D008081:Liposomes; D008565:Membrane Proteins; D018832:Molecular Chaperones; D028861:Nuclear Pore Complex Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; C094493:ran-binding protein 2; C487039:ARL1 protein, S cerevisiae; D020559:Monomeric GTP-Binding Proteins