Molecular insights into vesicle tethering at the Golgi by the Conserved Oligomeric Golgi (COG) complex and the golgin TMF

Victoria J Miller, Prateek Sharma, Tetyana A Kudlyk, Laura Frost, Adam P Rofe, Irene J Watson, Rainer Duden, Martin Lowe, Vladimir V Lupashin, Daniel Ungar

Research output: Contribution to journalArticlepeer-review


Protein sorting between eukaryotic compartments requires vesicular transport, wherein tethering provides the first contact between vesicle and target membranes. Here we map and start to functionally analyse the interaction network of the conserved oligomeric Golgi (COG) complex that mediates retrograde tethering at the Golgi. The found interactions of COG's subunits with members of transport factor families assign the individual subunits as specific interaction hubs. Functional analysis of selected interactions suggests a mechanistic tethering model. We find that the COG complex interacts with two different Rabs in addition to each end of the golgin "TATA element modulatory factor" (TMF). This allows COG to potentially bridge the distance between the golgin's distal end and the target membrane thereby promoting tighter docking. Concurrently we show that the central portion of TMF can bind to Golgi membranes that are liberated of their COPI cover. This latter interaction could serve to bring vesicle and target membranes into close apposition prior to fusion. A target selection mechanism, in which a hetero-oligomeric tethering factor organises Rabs and coiled transport factors to enable protein sorting specificity, could be applicable to vesicle targeting throughout eukaryotic cells.
Original languageEnglish
Pages (from-to)4229-4240
Number of pages12
JournalJournal of Biological Chemistry
Issue number6
Early online date13 Dec 2012
Publication statusPublished - 8 Feb 2013

Cite this