title: Interaction of MHC class I molecules with the transporter associated with antigen processing.
abstract: The transporter associated with antigen processing (TAP) delivers cytosolic peptides into the endoplasmic reticulum (ER) where they bind to nascent class 1 histocompatibility molecules. Class 1-peptide complexes are then displayed at the cell surface for recognition by cytotoxic T lymphocytes. Immunoprecipitation of either TAP or class 1 molecules revealed an association between the transporter and diverse class 1 products. TAP bound preferentially to heterodimers of the class 1 heavy chain and beta 2-microglobulin, and the complex subsequently dissociated in parallel with transport of class 1 molecules from the ER to the Golgi apparatus. The TAP-class 1 complexes could also be dissociated in vitro by the addition of class 1-binding peptides. The association of class 1 molecules with TAP likely promotes efficient capture of peptides before their exposure to the lumen of the ER.
authors.affiliation: Department of Biochemistry, University of Toronto, Ontario, Canada.
authors.forename: W K
authors.initials: WK
authors.lastname: Suh
authors.forename: M F
authors.initials: MF
authors.lastname: Cohen-Doyle
authors.forename: K
authors.initials: K
authors.lastname: Fruh
authors.forename: K
authors.initials: K
authors.lastname: Wang
authors.forename: P A
authors.initials: PA
authors.lastname: Peterson
authors.forename: D B
authors.initials: DB
authors.lastname: Williams
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D001692:Biological Transport; D002352:Carrier Proteins / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006183:H-2 Antigens / Q000378:metabolism*; D007106:Immune Sera; D051379:Mice; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011485:Protein Binding; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D006183:H-2 Antigens; D007106:Immune Sera; C073119:TAP1 protein, human; C486171:Tap1 protein, mouse; C489516:Tap2 protein, mouse; D001613:beta 2-Microglobulin; C071692:TAP2 protein, human