Folding and Assembly of Major Histocompatibility Complex Class I Heterodimers in the Endoplasmic Reticulum of Intact Cells Precedes the Binding of Peptide
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General Medicine
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Major histocompatibility complex (MHC) class I molecules are heterotrimers consisting of a polymorphic H chain, beta 2-microglobulin (beta 2m) and peptide. Peptides are thought to associate early during biosynthesis but the order of assembly of class I molecules from their component subunits in intact cells is not settled. We have studied the assembly of MHC class I molecules in intact cells with or without peptide transporters. MHC class I H chain/beta 2m heterodimers can be efficiently recovered only 4 min after translation and are preceded by a folding intermediate. Approximately 2 min after their formation, the class I heterodimers are loaded with peptides resulting in stable class I heterotrimers. In these in vivo studies, no evidence was obtained that peptide binding to the H chain preceded the association with beta 2m. In contrast, nonassembled class I H chains could be recovered immediately after translation, but this pool did not participate in the formation of class I molecules.
Philippou Y, Sjoberg H, Murphy E, Alyacoubi S, Jones K, Gordon-Weeks A Br J Cancer. 2020; 123(7):1089-1100.
PMID: 32641865 PMC: 7525450. DOI: 10.1038/s41416-020-0956-x.
Zhang Q, Liu K, Yue C, Zhang D, Lu D, Xiao W J Virol. 2020; 94(17).
PMID: 32522857 PMC: 7431782. DOI: 10.1128/JVI.00396-20.
The first step of peptide selection in antigen presentation by MHC class I molecules.
Garstka M, Fish A, Celie P, Joosten R, Janssen G, Berlin I Proc Natl Acad Sci U S A. 2015; 112(5):1505-10.
PMID: 25605945 PMC: 4321303. DOI: 10.1073/pnas.1416543112.
Lin J, Eggensperger S, Hank S, Wycisk A, Wieneke R, Mayerhofer P PLoS Pathog. 2014; 10(12):e1004554.
PMID: 25503639 PMC: 4263761. DOI: 10.1371/journal.ppat.1004554.
Pulse-chase analysis for studies of MHC class II biosynthesis, maturation, and peptide loading.
Hou T, Rinderknecht C, Hadjinicolaou A, Busch R, Mellins E Methods Mol Biol. 2013; 960:411-432.
PMID: 23329504 PMC: 4159250. DOI: 10.1007/978-1-62703-218-6_31.