TAPBPR bridges UDP-glucose:glycoprotein glucosyltransferase 1 onto MHC class I to provide quality control in the antigen presentation pathway

Autor: Andreas Neerincx, Clemens Hermann, Robin Antrobus, Andy van Hateren, Huan Cao, Nico Trautwein, Stefan Stevanović, Tim Elliott, Janet E Deane, Louise H Boyle
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: eLife, Vol 6 (2017)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.23049
Popis: Recently, we revealed that TAPBPR is a peptide exchange catalyst that is important for optimal peptide selection by MHC class I molecules. Here, we asked whether any other co-factors associate with TAPBPR, which would explain its effect on peptide selection. We identify an interaction between TAPBPR and UDP-glucose:glycoprotein glucosyltransferase 1 (UGT1), a folding sensor in the calnexin/calreticulin quality control cycle that is known to regenerate the Glc1Man9GlcNAc2 moiety on glycoproteins. Our results suggest the formation of a multimeric complex, dependent on a conserved cysteine at position 94 in TAPBPR, in which TAPBPR promotes the association of UGT1 with peptide-receptive MHC class I molecules. We reveal that the interaction between TAPBPR and UGT1 facilities the reglucosylation of the glycan on MHC class I molecules, promoting their recognition by calreticulin. Our results suggest that in addition to being a peptide editor, TAPBPR improves peptide optimisation by promoting peptide-receptive MHC class I molecules to associate with the peptide-loading complex.
Databáze: Directory of Open Access Journals