Coatomer Protein Complex Subunit Beta 2 (COPb2)

The Golgi coatomer complex constitutes the coat of nonclathrin-coated vesicles and is essential for Golgi budding and vesicular trafficking. It consists of 7 protein subunits, including COPB2.By screening human cDNA expression libraries, they isolated a cDNA encoding p102, or COPB2. The deduced 906-amino acid protein contains 6 N-terminal WD40 repeats and a leu-asp-asp (LDD) motif at the C terminus, like mouse Tcp1. Biochemical fractionation, immunoprecipitation, and Western blot analyses showed that COPB2 is a component of a 500- to 600-kD coatomer protein complex that includes COPB. Immunofluorescence microscopy demonstrated that COPB and COPB2 disperse from Golgi membranes in the presence of brefeldin A.