Related Experiment Video

Updated: May 16, 2026

Quantitative Localization of a Golgi Protein by Imaging Its Center of Fluorescence Mass
13:08

Quantitative Localization of a Golgi Protein by Imaging Its Center of Fluorescence Mass

Published on: August 10, 2017

Molecular insights into vesicle tethering at the Golgi by the conserved oligomeric Golgi (COG) complex and the golgin

Victoria J Miller1, Prateek Sharma, Tetyana A Kudlyk

  • 1Department of Biology, University of York, York, YO10 5DD, United Kingdom.

The Journal of Biological Chemistry
|December 15, 2012
PubMed

Insights

The conserved oligomeric Golgi (COG) complex acts as a key tethering factor in eukaryotic cells. It organizes transport factors and Rabs to ensure precise protein sorting via vesicular transport.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Vesicular transport is crucial for protein sorting between eukaryotic compartments.
  • Tethering factors mediate the initial contact between vesicles and target membranes.
  • The conserved oligomeric Golgi (COG) complex is involved in retrograde tethering at the Golgi apparatus.

Purpose of the Study:

  • To map and functionally analyze the interaction network of the COG complex.
  • To elucidate the role of COG in mediating retrograde tethering at the Golgi.
  • To propose a mechanistic tethering model for protein sorting specificity.

Main Methods:

  • Interaction network mapping of COG complex subunits.
  • Functional analysis of COG subunit interactions with transport factors and Rabs.
  • Investigation of TATA element modulatory factor (TMF) interactions with COG and Golgi membranes.

Main Results:

  • COG subunits function as specific interaction hubs within the transport factor network.
  • COG interacts with two Rabs and both ends of TMF, potentially bridging membrane distances for tighter docking.
  • TMF's central portion binds to COPI-depleted Golgi membranes, facilitating vesicle-membrane apposition before fusion.

Conclusions:

  • The COG complex plays a critical role in tethering and protein sorting at the Golgi.
  • A model is proposed where COG organizes Rabs and coiled-coil factors for specific vesicle targeting.
  • This mechanism of hetero-oligomeric tethering factor organization may be broadly applicable to vesicle targeting in eukaryotes.

More Related Videos

Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay09:19

Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay

Published on: October 19, 2012

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy10:58

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

Published on: August 24, 2016

Related Concept Videos

Coat Assembly and GTPases01:33

Coat Assembly and GTPases

Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Vesicular Tubular Clusters01:45

Vesicular Tubular Clusters

After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
Transport Across the Golgi01:26

Transport Across the Golgi

While it is unclear how molecules move between adjacent Golgi cisternae, it is apparent that the molecules move from cis- cisterna, the entry face, to the trans- cisterna, the exit face. Experiments initially suggested vesicles that bud from one cisterna and fuse with the next cisterna to transport proteins between the cisternae. This vesicular transport model describes the Golgi apparatus as a relatively static structure with a unique enzyme composition in each cisterna. Molecules are...
Clathrin Coated Vesicles01:12

Clathrin Coated Vesicles

Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
Pinching-off of Coated Vesicles01:32

Pinching-off of Coated Vesicles

Vesicle budding is orchestrated by distinct cytosolic proteins such as adaptor proteins, coat proteins, and GTPases. To initiate vesicle budding, membrane-bending proteins containing crescent-shaped BAR domains bind to the lipid heads in the bilayer and distort the membrane to form a protein-coated vesicle bud. Adaptors proteins such as AP2 for clathrin-coated vesicles can nucleate on the deformed membrane. Finally, coat proteins such as clathrin or COPI and COPII assemble into a coat forming...
SNAREs and Membrane Fusion01:43

SNAREs and Membrane Fusion

Once a transport vesicle has recognized its target organelle, the vesicular membrane needs to fuse with the target membrane to unload the cargo. Transmembrane proteins called SNAREs present on organelle membranes and their vesicles, mediate vesicle fusion.
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...