Reconstitution of glycan-driven MHC-I recycling reveals calreticulin as mediator between TAPBPR and tapasin

ABSTRACT: Protein folding in the endoplasmic reticulum (ER) relies on N-linked glycosylation and glycan remodeling to guide quality control. Major histocompatibility complex class I (MHC-I) molecules, essential for adaptive immunity, undergo a specialized maturation pathway involving the peptide-loading complex (PLC), the editor TAPBPR, the UDP-glucose:glycoprotein glucosyltransferase, and the lectin chaperone calreticulin. However, how glycan-dependent mechanisms coordinate MHC-I transfer between these factors has remained unclear. Using a fully reconstituted system, we show that retrograde transfer of peptide-receptive MHC-I from TAPBPR to tapasin requires calreticulin recognition of monoglucosylated MHC-I glycans. While calreticulin's C-terminal acidic helix is dispensable for releasing reglucosy

SUBMITTER: Tim, Julius Heinke 

PROVIDER: S-SCDT-10_1038-S44318-026-00873-2 | biostudies-other |

REPOSITORIES: biostudies-other