COPII vesicles get supersized by ubiquitin.

Some proteins are too big to fit into conventional COPII-coated vesicles, which raises the question of how large cargo, such as procollagen fibrils, are exported from the endoplasmic reticulum. Jin et al. (2012) in Nature now report that the creation of oversized vesicles is facilitated by the ubiquitination of the COPII component Sec31p.