Mechanisms of vesicle formation: insights from the COP system

The major cytosolic and membrane proteins that represent machinery of coat protein (COP)-coated transport vesicles within the secretory pathway are ch aracterized to date. This has allowed investigation of the molecular mechan isms that underlie the formation of these vesicles. In vitro binding studie s and reconstitution experiments have provided insights at the molecular le vel into the biogenesis of COPII- and COPI-coated vesicles.