Taxonomic distribution of proteins containing COG6 domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing COG6 domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Characterization of a mammalian Golgi-localized protein complex, COG, thatis required for normal Golgi morphology and function.

Ungar D, Oka T, Brittle EE, Vasile E, Lupashin VV, Chatterton JE, Heuser JE, Krieger M, Waters MG
J Cell Biol. 2002; 157: 405-15

Multiprotein complexes are key determinants of Golgi apparatus structureand its capacity for intracellular transport and glycoproteinmodification. Three complexes that have previously been partiallycharacterized include (a) the Golgi transport complex (GTC), identified inan in vitro membrane transport assay, (b) the ldlCp complex, identified inanalyses of CHO cell mutants with defects in Golgi-associatedglycosylation reactions, and (c) the mammalian Sec34 complex, identifiedby homology to yeast Sec34p, implicated in vesicular transport. We showthat these three complexes are identical and rename them the conservedoligomeric Golgi (COG) complex. The COG complex comprises four previouslycharacterized proteins (Cog1/ldlBp, Cog2/ldlCp, Cog3/Sec34, andCog5/GTC-90), three homologues of yeast Sec34/35 complex subunits (Cog4,-6, and -8), and a previously unidentified Golgi-associated protein(Cog7). EM of ldlB and ldlC mutants established that COG is required fornormal Golgi morphology. "Deep etch" EM of purified COG revealed anapproximately 37-nm-long structure comprised of two similarly sizedglobular domains connected by smaller extensions. Consideration ofbiochemical and genetic data for mammalian COG and its yeast homologuesuggests a model for the subunit distribution within this complex, whichplays critical roles in Golgi structure and function.

The Sec34/35 Golgi transport complex is related to the exocyst, defining afamily of complexes involved in multiple steps of membrane traffic.

Whyte JR, Munro S
Dev Cell. 2001; 1: 527-37

The specificity of intracellular vesicle transport is mediated in part bytethering factors that attach the vesicle to the destination organelleprior to fusion. We have identified a protein, Dor1p, that is involved invesicle targeting to the yeast Golgi apparatus and found it to beassociated with seven further proteins. Identification of these revealedthat they include Sec34p and Sec35p, the two known components of theSec34/35 complex previously proposed to tether vesicles to the Golgi. Ofthe six previously uncharacterized components, four have homologs inhigher eukaryotes, including a subunit of a mammalian Golgi transportcomplex. Furthermore, several of the proteins show distant homology tocomponents of two other putative tethering complexes, the exocyst and theVps52/53/54 complex, revealing that tethering factors involved indifferent membrane traffic steps are structurally related.