Role for ribosome-associated quality control in sampling proteins for MHC class I-mediated antigen presentation

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 117; no. 8; pp. 4099 - 4108
• Main Authors: Trentini, Débora Broch, Pecoraro, Matteo, Tiwary, Shivani, Cox, Jürgen, Mann, Matthias, Hipp, Mark S., Hartl, F. Ulrich
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 25-02-2020
• Subjects: Adaptive systems; Animals; Antigen presentation; Antigen Presentation - physiology; Antigens; Biodegradation; Biological Sciences; Degradation; Epitopes - metabolism; Gene Deletion; Gene Expression Regulation; HeLa Cells; Histocompatibility Antigens Class I - physiology; Humans; Immune system; Major histocompatibility complex; Mammalian cells; Mass spectrometry; Mass spectroscopy; Peptides; Polypeptides; Proteasomes; Proteins; Proteomes; Quality control; Ribosomes - physiology; RNA, Messenger - genetics; RNA, Messenger - metabolism; Stalling; Substrates; Ubiquitin-Protein Ligases - metabolism; immunopeptidome; MHC-I; ribosome-associated quality control; Listerin
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1914401117

Mammalian cells present a fingerprint of their proteome to the adaptive immune system through the display of endogenous peptides on MHC-I complexes. MHC-I–bound peptides originate from protein degradation by the proteasome, suggesting that stably folded, long-lived proteins could evade monitoring. Here, we investigate the role in antigen presentation of the ribosome-associated quality control (RQC) pathway for the degradation of nascent polypeptides that are encoded by defective messenger RNAs and undergo stalling at the ribosome during translation. We find that degradation of model proteins by RQC results in efficient MHC-I presentation, independent of their intrinsic folding properties. Quantitative profiling of MHC-I peptides in wild-type and RQC-deficient cells by mass spectrometry showed that RQC substantially contributes to the composition of the immunopeptidome. Our results also identify endogenous substrates of the RQC pathway in human cells and provide insight into common principles causing ribosome stalling under physiological conditions.