Vesicle Transport: Springing the TRAPP

Vesicle Transport: Springing the TRAPP

When a coated transport vesicle docks with its target membrane, the coat proteins and docking machinery must be released before the membranes can fuse. A recent paper shows how this disassembly is triggered at precisely the right time.

The Architecture of the Multisubunit TRAPP I Complex Suggests a Model for Vesicle Tethering

Transport protein particle (TRAPP) I is a multisubunit vesicle tethering factor composed of seven subunits involved in ER-to-Golgi trafficking. The functional mechanism of the complex and how the subunits interact to form a functional unit are unknown. Here, we have used a multidisciplinary approach that includes X-ray crystallography, electron microscopy, biochemistry, and yeast genetics to el...

TRAPP stably associates with the Golgi and is required for vesicle docking.

Bet3p, a component of a large novel complex called TRAPP, acts upstream of endoplasmic reticulum (ER)-Golgi SNAREs. Unlike the SNAREs, which reside on multiple compartments, Bet3p is localized exclusively to Golgi membranes. While other proteins recycle from the Golgi to the ER, Bet3p and other TRAPP subunits remain associated with this membrane under conditions that block anterograde traffic. ...

TRAPP, a highly conserved novel complex on the cis-Golgi that mediates vesicle docking and fusion.

We previously identified BET3 by its genetic interactions with BET1, a gene whose SNARE-like product acts in endoplasmic reticulum (ER)-to-Golgi transport. To gain insight into the function of Bet3p, we added three c-myc tags to its C-terminus and immunopurified this protein from a clarified detergent extract. Here we report that Bet3p is a member of a large complex ( approximately 800 kDa) tha...

Vesicle transport in chloroplasts