A Golgi retention signal in a membrane-spanning domain of coronavirus E1 protein

These results were confirmed and quantitated by analyzing the processing of the N-linked oligosaccharides . The two oligosaccharides of the nonretained El mutant protein Oml,2 are processed to an endo H-resistant, polylactosamine-containing form as the protein is transported through the Golgi complex to the plasma membrane (27) . Since the processed form is heterogeneous, it is difficult to quantitate on SDS gels. To determine the fraction of each protein with processed oligosaccharides, we subtracted the amount ofunprocessed material (endo H sensitive) from the total (Nglycanase sensitive ; Fig . 8 ) . As shown in the quantitation below the lanes, Om2,3/QI3,, and Am2,3/ins were the most efficiently transported, with 90 and 85 % endo H-resistant oligosaccharides after a 3-h chase, respectively.