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Updated: Aug 13, 2026

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro
Published on: January 11, 2017
Reconstitution of cargo-dependent COPII coat assembly on proteoliposomes
1Molecular Membrane Biology Laboratory, RIKEN, Discovery Research Institute, Saitama, Japan.
Abstract:
The coat protein complex II (COPII) coat is responsible for direct capture of membrane cargo proteins and for the physical deformation of the endoplasmic reticulum (ER) membrane that drives the transport vesicle formation. The use of an in vitro reconstitution system comprising purified components is desirable for studies aimed at elucidating the role(s) of individual proteins in a specific biochemical reaction. To investigate the assembly-disassembly of COPII coats in a completely reconstituted reaction, we have developed a synthetic budding reaction involving purified coat proteins and cargo-reconstituted proteoliposomes. We describe here a fluorescence resonance energy transfer (FRET)-based method for monitoring the kinetics of COPII coat complex assembly and disassembly in cargo-reconstituted proteoliposomes. This assay allows comparison of the time course of the coat disassembly from the cargo as monitored by FRET signal with the time course of accompanying Sar1p GTP hydrolysis by tryptophan fluorescence.
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