Tubulin is a major protein constituent of bovine brain coated vesicles

A major protein constituent of coated vesicles derived from bovine brain is present as a Mr = 55,000 protein doublet on SDS-polyacrylamide gels. This protein comigrates with purified calf brain tubulin after two-dimensional electrophoresis, binds tubulin antibody and has two-dimensional tryptic peptide maps identical to those of purified tubulin. The results indicate that tubulin is a major protein constituent of coated vesicles. Coated vesicles had no significant effect on the polymerization rate of purified tubulin. Therefore, the physiological relevance of tubulin associated with coated vesicles remains to be determined.