Reactome | Loading of antigen peptide onto MHC class I molecule

Loading of antigen peptide onto MHC class I molecule

Stable Identifier

R-HSA-1236943

Type

Reaction [binding]

Species

Homo sapiens

Compartment

early endosome lumen, early endosome membrane

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Loading of antigen peptide onto MHC class I molecule

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Peptides generated by Cathepsin S or IRAP-mediated proteolysis in the endosomes are loaded onto MHC class I molecules, which are internalized and transported to early and late endosomal compartments where antigenic peptides can be loaded. A fraction of the internalized cell surface class I molecules enter MHC class II compartments (MIICs) within endocytic vesicles (Gromme et al. 1999, Kleijmeer et al. 2001). Microscopic analysis has revealed that surface MHC-I molecules are internalized and transported to early and late endosomal compartments (Basha et al. 2008, Lizee et al. 2003). A tyrosine-based endocytic trafficking motif (YXXA) is required for the constitutive internalization of MHC-I molecules from the cell surface into early/late endosomes for peptide loading (Basha et al. 2008, Lizee et al. 2003). Upon entry in to these endosomal compartments the MHC class I complexes exchange their pre-bound peptides with exogenously derived antigenic peptides.

Literature References

PubMed ID	Title	Journal	Year
18802471	MHC class I endosomal and lysosomal trafficking coincides with exogenous antigen loading in dendritic cells Basha, G, Lizée, G, Reinicke, AT, Seipp, RP, Omilusik, KD, Jefferies, WA	PLoS One	2008
11247303	Antigen loading of MHC class I molecules in the endocytic tract Kleijmeer, MJ, Escola, JM, Uytdehaag, FG, Jakobson, E, Griffith, JM, Osterhaus, AD, Stoorvogel, W, Melief, CJ, Rabouille, C, Geuze, HJ	Traffic	2001
10468607	Recycling MHC class I molecules and endosomal peptide loading Grommé, M, Uytdehaag, FG, Janssen, H, Calafat, J, van Binnendijk, RS, Kenter, MJ, Tulp, A, Verwoerd, D, Neefjes, J	Proc Natl Acad Sci U S A	1999