These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The MHC class II-associated invariant chain: a molecule with multiple roles in MHC class II biosynthesis and antigen presentation to CD4+ T cells.
    Author: Bertolino P, Rabourdin-Combe C.
    Journal: Crit Rev Immunol; 1996; 16(4):359-79. PubMed ID: 8954255.
    Abstract:
    The MHC class II-associated invariant chain (Ii) plays a central role in the biological function of MHC class II molecules. Ii is a type II membrane glycoprotein that is synthesized as different isoforms that include a major 31 kDa isoform (p31/p33) and a minor 41 kDa isoform (p41) in both, mice and humans. All isoforms share several common regions acting at different steps in the process that lead to functional class II molecule/peptide complexes. In the ER, two C-terminal extracytoplasmic regions of Ii are required for class II assembly: the 153-183 region is involved in the formation of Ii trimers and the 80-104 region mediates binding with class II molecules giving rise to nonamers. Ii association with class II molecules prevents both aggregation of class II dimers and binding with endogenous ER-derived peptides. In addition, two motifs in the cytosolic N-terminal region of Ii direct class II nonamers toward specialized endosomal compartments where peptide loading occurs. In these compartments, Ii undergoes proteolytic degradation leaving only CLIP (residues 80-104) associated with Class II. CLIP modulates loading of class II molecules in endosomes and is removed from the MHC class II groove by monomorphic MHC class II molecules, H2-M or HLA DM, in mouse and human, respectively. The roles of Ii in antigen presentation to MHC class II-restricted T cells and in CD4+ T cell development are discussed in this review.
    [Abstract] [Full Text] [Related] [New Search]