Related Experiment Video
Updated: Jul 23, 2026

Analysis of Endocytic Uptake and Retrograde Transport to the Trans-Golgi Network Using Functionalized Nanobodies in Cultured Cells
Published on: February 21, 2019
TRAPP I implicated in the specificity of tethering in ER-to-Golgi transport
M Sacher1, J Barrowman, W Wang
1Department of Cell Biology, Yale University, New Haven, CT 06520, USA.
Abstract:
TRAPP is a conserved protein complex required early in the secretory pathway. Here, we report two forms of TRAPP, TRAPP I and TRAPP II, that mediate different transport events. Using chemically pure TRAPP I and COPII vesicles, we have reconstituted vesicle targeting in vitro. The binding of COPII vesicles to TRAPP I is specific, blocked by GTPgammaS, and, surprisingly, does not require other tethering factors. Our findings imply that TRAPP I is the receptor on the Golgi for COPII vesicles. Once the vesicle binds to TRAPP I, the small GTP binding protein Ypt1p is activated and other tethering factors are recruited.
Related Concept Videos
Vesicular Tubular Clusters
With the help of motor proteins such...
ER Retrieval Pathway
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
Tail-anchoring of Proteins in the ER Membrane
GPI Anchoring of Proteins in the ER Membrane
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
Protein Translocation Machinery on the ER Membrane
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.
Rab Cascades

