Protein Processing, Post-TranslationalTunicamycinGlycosylationIndolizinesSwainsonine1-DeoxynojirimycinGlucosamineAmino Acid SequenceMolecular Sequence DataMembrane Transport ProteinsEndoplasmic ReticulumCell LineProtein Modification, TranslationalAcetylglucosamineMass SpectrometryCongenital Disorders of GlycosylationPolysaccharidesProteinsLysineAldehydesSUMO-1 ProteinSpectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationSmall Ubiquitin-Related Modifier ProteinsN-AcetylglucosaminyltransferasesGlycoproteinsMutationProteomicsAcetylationProtein BindingAsparagineCysteineBase SequenceSumoylationTandem Mass SpectrometryElectrophoresis, Polyacrylamide Gel