151. Structural insights into human MHC-II association with invariant chain.
- Author
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Nan Wang, Waghray, Deepa, Caveney, Nathanael A., Jude, Kevin M., and Garcia, K. Christopher
- Subjects
MAJOR histocompatibility complex ,TRANSMEMBRANE domains ,PEPTIDES ,ANTIGEN presentation ,CELLULAR immunity - Abstract
The loading of processed peptides on to major histocompatibility complex II (MHC-II) molecules for recognition by T cells is vital to cell-mediated adaptive immunity. As part of this process, MHC-II associates with the invariant chain (Ii) during biosynthesis in the endoplasmic reticulum to prevent premature peptide loading and to serve as a scaffold for subsequent proteolytic processing into MHC-II-CLIP. Cryo-electron microscopy structures of full-length Human Leukocyte Antigen-DR (HLA-DR) and HLA-DQ complexes associated with Ii, resolved at 3.0 to 3.1 Å, elucidate the trimeric assembly of the HLA/Ii complex and define atomic-level interactions between HLA, Ii transmembrane domains, loop domains, and class II-associated invariant chain peptides (CLIP). Together with previous structures of MHC-II peptide loading intermediates DO and DM, our findings complete the structural path governing class II antigen presentation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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