YEAST COATOMER CONTAINS A SUBUNIT HOMOLOGOUS TO MAMMALIAN BETA'-COP

The homologue of the mammalian coatomer complex was isolated from yeas t cytosol and separated on a modified urea-containing SDS-polyacrylami de gel system. An additional band in the 100 kDa molecular weight rang e appeared when compared to the protein pattern obtained in convention al Laemmli gels, exactly as observed for mammalian coatomer. Cross-rea ctivity with an anti-peptide antibody raised against the C-terminus of beta'-COP from bovine, and N-terminal sequence analysis, revealed tha t this protein from yeast is related to beta'-COP from mammals.