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Updated: Jun 23, 2026

Purification of the Membrane Compartment for Endoplasmic Reticulum-associated Degradation of Exogenous Antigens in Cross-presentation
Published on: August 21, 2017
The peptide-loading complex--antigen translocation and MHC class I loading
Christian Schölz1, Robert Tampé
1Institute of Biochemistry, Biocenter, Center for Membrane Proteomics (CMP) and Cluster of Excellence (CEF)-Macromolecular Complexes, Goethe University Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt/Main, Germany.
Abstract:
A large and dynamic membrane-associated machinery orchestrates the translocation of antigenic peptides into the endoplasmic reticulum (ER) lumen for subsequent loading onto major histocompatibility complex (MHC) class I molecules. The peptide-loading complex ensures that only high-affinity peptides, which guarantee long-term stability of MHC I complexes, are presented to T-lymphocytes. Adaptive immunity is dependent on surface display of the cellular proteome in the form of protein fragments, thus allowing efficient recognition of infected or malignant transformed cells. In this review, we summarize recent findings of antigen translocation by the transporter associated with antigen processing and loading of MHC class I molecules in the ER, focusing on the mechanisms involved in this process.
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