Related Experiment Video
Updated: Aug 8, 2026

Measuring TCR-pMHC Binding In Situ using a FRET-based Microscopy Assay
Published on: October 30, 2015
Assembly of major histocompatibility complex class II subunits with invariant chain
1Division of Immunobiology, Institute of Molecular Physiology, University of Bonn, Romerstrasse 164, 53117 Bonn, Germany.
Abstract:
The highly polymorphic major histocompatibility complex class II (MHCII) polypeptides assemble in the ER with the assistance of invariant chain (Ii) chaperone. Ii binds to the peptide-binding pocket of MHCII heterodimers. We explored the mechanism how MHCII subunits attach to Ii. Expression with single alpha or beta subunits from three human HLA and two mouse H2 class II isotypes revealed that Ii co-isolates predominantly with the alpha polypeptide. Co-isolation with alpha chain requires the groove binding Ii-segment and depends on M91 of Ii. Immunoprecipitation of Ii from pulse chase labeled cells showed sequential assembly of alpha and beta chains.
Related Concept Videos
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Antigens Involved in Adaptive Immunity
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Antigen Processing Pathways
MHC Class I: Presenting Endogenous...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...

