title: Cog1p plays a central role in the organization of the yeast conserved oligomeric Golgi complex.
abstract: The conserved oligomeric Golgi (COG) complex is an evolutionarily conserved peripheral membrane oligomeric protein complex that is involved in intra-Golgi protein trafficking. The COG complex is composed of eight subunits that are located in two lobes; Lobe A contains COG1-4, and Lobe B is composed of COG5-8. Both in vivo and in vitro protein-protein interaction techniques were applied to characterize interactions between individual COG subunits. In vitro assays revealed binary interactions between Cog2p and Cog3p, Cog2p and Cog4p, and Cog6p and Cog8p and a strong interaction between Cog5p and Cog7p. The two-hybrid assay confirmed these findings and revealed that Cog1p interacted with subunits from both lobes of the complex. Antibodies to COG subunits were utilized to determine the protein levels and membrane association of COG subunits in yeast delta cog1-8 mutants. As a result, we created a model of the protein-protein interactions within the yeast COG complex and proposed that Cog1p is a bridging subunit between the two COG lobes. In support of this hypothesis, we have demonstrated that Cog1p is required for the stable association between two COG subcomplexes.
authors.affiliation: Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
authors.forename: Pierre
authors.initials: P
authors.lastname: Fotso
authors.forename: Yulia
authors.initials: Y
authors.lastname: Koryakina
authors.forename: Oleksandra
authors.initials: O
authors.lastname: Pavliv
authors.forename: Arnold B
authors.initials: AB
authors.lastname: Tsiomenko
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Lupashin
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000378:metabolism; D002850:Chromatography, Gel; D003600:Cytosol / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000502:physiology*; D017353:Gene Deletion; D005821:Genetic Techniques; D005838:Genotype; D005982:Glutathione Transferase / Q000378:metabolism; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism*; D015151:Immunoblotting; D047468:Immunoprecipitation; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D050765:Qa-SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000502:physiology*
chemical_list: C112749:COG2 protein, S cerevisiae; C439910:COG8 protein, S cerevisiae; C503913:Cog1 protein, S cerevisiae; D005656:Fungal Proteins; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; C077554:Sed5 protein, S cerevisiae; D033921:Vesicular Transport Proteins; D005982:Glutathione Transferase