Peptide selection by MHC-encoded TAP transporters.
With the discovery of MHC-encoded peptide transporters (TAP) came the identification of a new class of molecules within the immune system. TAP belongs to a large family of ATP-binding, multimembrane-spanning transporters that are expressed in a diversity of cells, from prokaryotic to mammalian, and show specificity for a variety of different substrates. TAP represents the solution to a major topological problem in immunology, namely the translocation of peptides, generated by cytosolic degradation of antigens, into the lumen of the endoplasmic reticulum where they associate with newly synthesized MHC class I molecules. A novel assay allows us to determine the requirements for the TAP-mediated peptide transport. First results indicate that TAP preselects peptides according to sequence and length in a way that is compatible with the characteristics of peptides isolated from class I molecules.
Momburg
F
F
Tumor Immunology Program, German Cancer Research Center, Heidelberg.
Neefjes
J J
JJ
Hämmerling
G J
GJ
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D000941:Antigens / Q000378:metabolism*; D001692:Biological Transport; D002352:Carrier Proteins / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D008285:Major Histocompatibility Complex / Q000276:immunology*; D010455:Peptides / Q000276:immunology* / Q000378:metabolism
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D000941:Antigens; D002352:Carrier Proteins; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D010455:Peptides; C073119:TAP1 protein, human; C071692:TAP2 protein, human