Coatomer Protein Complex Subunit Epsilon (COPe)

COPe is an epsilon subunit of coatomer protein complex. Coatomer is a cytosolic protein complex that binds to dilysine motifs and reversibly associates with Golgi non-clathrin-coated vesicles. It is required for budding from Golgi membranes, and is essential for the retrograde Golgi-to-ER transport of dilysine-tagged proteins. Coatomer complex consists of at least the alpha, beta, beta', gamma, delta, epsilon and zeta subunits. Alternatively spliced transcript variants encoding different isoforms have been identified.

Time-lapse microscopy showed that COPE, as a marker of COPI, is found on tubulovesicular transport complexes shuttling anterograde, but rarely retrograde, cargo to the Golgi complex.