Insights into COPI coat assembly and function in living cells.

Eukaryotic cells use an elaborate machinery involving the COPI coat complex to control protein trafficking in the secretory pathway. Although individual components of this complex are well known and their roles in deforming lipid membranes into coated carriers are well described, the precise sequence of molecular events by which these components assemble into and release from the COPI coat lattice remains unclear. Here, we present images and movies characterizing the dynamics of protein components of the COPI coat in living cells. We discuss the self-assembly of these coat components into a molecular machine for sorting and trafficking membranes.