Loading of antigen peptide onto MHC class I molecule

Stable Identifier
Reaction [binding]
Homo sapiens
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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
11247303 Antigen loading of MHC class I molecules in the endocytic tract

Osterhaus, AD, Griffith, JM, Jakobson, E, Kleijmeer, MJ, Escola, JM, Stoorvogel, W, Rabouille, C, Uytdehaag, FG, Geuze, HJ, Melief, CJ

Traffic 2001
18802471 MHC class I endosomal and lysosomal trafficking coincides with exogenous antigen loading in dendritic cells

Basha, G, Seipp, RP, Lizée, G, Omilusik, KD, Jefferies, WA, Reinicke, AT

PLoS One 2008
10468607 Recycling MHC class I molecules and endosomal peptide loading

Neefjes, J, Tulp, A, Calafat, J, Grommé, M, Kenter, MJ, Janssen, H, Verwoerd, D, van Binnendijk, RS, Uytdehaag, FG

Proc Natl Acad Sci U S A 1999
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