title: Influence of N-glycan chain length on chaperone association and intracellular transport of major histocompatibility complex class I proteins.
abstract: Recent studies demonstrate that processing of N-linked glycans plays an important role in the quality control of major histocompatibility complex (MHC) class I transport from the endoplasmic reticulum (ER) to the Golgi complex and beyond. Here, we investigated the importance of oligosaccharide chain length on the association of MHC class I proteins with molecular chaperones and their intracellular transport from the ER to the Golgi. These data show that calnexin interaction with class I proteins having truncated N-glycans was reduced compared to normal class I molecules, whereas the assembly of class I with calreticulin and TAP was unperturbed by N-glycan chain length. Additionally, these results demonstrate that class I proteins containing truncated N-glycans showed decreased detachment from calreticulin and TAP relative to class I proteins bearing typical oligosaccharides. Taken together, these studies show that N-glycan chain length is an important determinant for the quality control of newly synthesized MHC class I proteins in the ER.
authors.affiliation: School of Medicine, East Carolina University, Greenville, North Carolina, 27858-4354, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Bennett
authors.forename: K P
authors.initials: KP
authors.lastname: Kearse
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D002135:Calcium-Binding Proteins / Q000378:metabolism; D037281:Calnexin; D037282:Calreticulin; D002240:Carbohydrate Sequence; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D006183:H-2 Antigens / Q000378:metabolism*; D051379:Mice; D018832:Molecular Chaperones / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D012261:Ribonucleoproteins / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D002135:Calcium-Binding Proteins; D037282:Calreticulin; D006023:Glycoproteins; D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D018832:Molecular Chaperones; D012261:Ribonucleoproteins; D001613:beta 2-Microglobulin; D037281:Calnexin