A specialized tyrosine-based endocytosis signal in MR1 controls antigen presentation to MAIT cells

Hui Jing Lim, Jacinta M. Wubben, Cristian Pinero Garcia, Sebastian Cruz-Gomez, Jieru Deng, Jeffrey Y.W. Mak, Abderrahman Hachani, Regan J. Anderson, Gavin F. Painter, Jesse Goyette, Shanika L. Amarasinghe, Matthew E. Ritchie, Antoine Roquilly, David P. Fairlie, Katharina Gaus, Jamie Rossjohn, Jose A. Villadangos, Hamish E.G. McWilliam

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3 Citations (Scopus)


MR1 is a highly conserved microbial immune-detection system in mammals. It captures vitamin B-related metabolite antigens from diverse microbes and presents them at the cell surface to stimulate MR1-restricted lymphocytes including mucosal-associated invariant T (MAIT) cells. MR1 presentation and MAIT cell recognition mediate homeostasis through host defense and tissue repair. The cellular mechanisms regulating MR1 cell surface expression are critical to its function and MAIT cell recognition, yet they are poorly defined. Here, we report that human MR1 is equipped with a tyrosine-based motif in its cytoplasmic domain that mediates low affinity binding with the endocytic adaptor protein 2 (AP2) complex. This interaction controls the kinetics of MR1 internalization from the cell surface and minimizes recycling. We propose MR1 uses AP2 endocytosis to define the duration of antigen presentation to MAIT cells and the detection of a microbial metabolic signature by the immune system.

Original languageEnglish
Article numbere202110125
Number of pages24
JournalJournal of Cell Biology
Issue number12
Publication statusPublished - 5 Dec 2022

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