Subunit architecture of the conserved oligomeric Golgi complex.
The conserved oligomeric Golgi (COG) complex is thought to function in intra-Golgi retrograde trafficking mediated by coat protein I vesicles, a pathway essential for the proper structure and function of the Golgi apparatus. Previous work suggested that COG might act as a tethering factor to mediate the initial attachment between coat protein I vesicles and Golgi membranes. Here, we present extensive in vitro co-translation and immunoprecipitation experiments leading to a new model for the overall architecture of the mammalian COG complex. The eight COG subunits (Cog1-8) are found to form two heterotrimeric subassemblies (Cog2/3/4 and Cog5/6/7) linked by a heterodimer composed of the remaining subunits (Cog1/8). This model is in excellent agreement with in vivo data presented in an accompanying paper (Oka, T., Vasile, E., Penman, M., Novina, C. D., Dykxhoorn, D. M., Ungar, D., Hughson, F. M., and Krieger, M. (2005) J. Biol. Chem. 280, 32736-32745).
Ungar
Daniel
D
Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
Oka
Toshihiko
T
Vasile
Eliza
E
Krieger
Monty
M
Hughson
Frederick M
FM
D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D006056:Golgi Apparatus / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D033942:Adaptor Proteins, Vesicular Transport; C486489:COG1 protein, human; C498528:COG3 protein, human; C115632:COG5 protein, human; D002352:Carrier Proteins; D008565:Membrane Proteins; D011506:Proteins; C090202:COG2 protein, human