Assembly and transport of MHC class II molecules.
At the surface of antigen-presenting cells MHC class I and class II molecules present peptides to respectively CD8+ and CD4+ T cells. MHC class I molecules acquire peptides right after synthesis in the endoplasmic reticulum. MHC class II molecules do not acquire peptides in the endoplasmic reticulum but instead associate with a third chain, the invariant chain which impedes peptide binding. Subsequently the invariant chain takes MHC class II molecules to the endosomal/lysosomal compartment thanks to a targeting signal retained in its cytoplasmic tail. It then dissociates from the MHC class II dimer to allow it to bind peptides.
Teyton
L
L
Department of Immunology, Scripps Research Institute, La Jolla, CA 92037.
Peterson
P A
PA
D001693:Biological Transport, Active; D005802:Genes, MHC Class II; D006681:HLA-D Antigens / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D008247:Lysosomes / Q000276:immunology; D010455:Peptides / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology
D006681:HLA-D Antigens; D015395:Histocompatibility Antigens Class I; D010455:Peptides