The BioGRID | PUBLICATION VIEW

	J. Cell Biol. Jan (2007); 176(3):255-61
The yeast orthologue of GRASP65 forms a complex with a coiled-coil protein that contributes to ER to Golgi traffic-
Behnia R, Barr FA, Flanagan JJ, Barlowe C, Munro S
Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 2QH, England, UK-
Abstract: The mammalian Golgi protein GRASP65 is required in assays that reconstitute cisternal stacking and vesicle tethering- Attached to membranes by an N-terminal myristoyl group, it recruits the coiled-coil protein GM130- The relevance of this system to budding yeasts has been unclear, as they lack an obvious orthologue of GM130, and their only GRASP65 relative -Grh1- lacks a myristoylation site and has even been suggested to act in a mitotic checkpoint- In this study, we show that Grh1 has an N-terminal amphipathic helix that is N-terminally acetylated and mediates association with the cis-Golgi- We find that Grh1 forms a complex with a previously uncharacterized coiled-coil protein, Ydl099w -Bug1-- In addition, Grh1 interacts with the Sec23-24 component of the COPII coat- Neither Grh1 nor Bug1 are essential for growth, but biochemical assays and genetic interactions with known mediators of vesicle tethering -Uso1 and Ypt1- suggest that the Grh1-Bug1 complex contributes to a redundant network of interactions that mediates consumption of COPII vesicles and formation of the cis-Golgi-
[PUBMED: 17261844]