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Proteasome isoforms exhibit only quantitative differences in cleavage and epitope generation
Author(s) -
Mishto Michele,
Liepe Juliane,
TextorisTaube Kathrin,
Keller Christin,
Henklein Petra,
Weberruß Marion,
Dahlmann Burkhardt,
Enenkel Cordula,
Voigt Antje,
Kuckelkorn Ulrike,
Stumpf Michael P. H.,
Kloetzel Peter M.
Publication year - 2014
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.201444902
Subject(s) - epitope , proteasome , biology , mhc class i , cleavage (geology) , gene isoform , major histocompatibility complex , peptide , protein subunit , antigen processing , antigen presentation , microbiology and biotechnology , antigen , biochemistry , genetics , immune system , t cell , gene , paleontology , fracture (geology)
Immunoproteasomes are considered to be optimised to process Ags and to alter the peptide repertoire by generating a qualitatively different set of MHC class I epitopes. Whether the immunoproteasome at the biochemical level, influence the quality rather than the quantity of the immuno‐genic peptide pool is still unclear. Here, we quantified the cleavage‐site usage by human standard‐ and immunoproteasomes, and proteasomes from immuno‐subunit‐deficient mice, as well as the peptides generated from model polypeptides. We show in this study that the different proteasome isoforms can exert significant quantitative differences in the cleavage‐site usage and MHC class I restricted epitope production. However, independent of the proteasome isoform and substrates studied, no evidence was obtained for the abolishment of the specific cleavage‐site usage, or for differences in the quality of the peptides generated. Thus, we conclude that the observed differences in MHC class I restricted Ag presentation between standard‐ and immunoproteasomes are due to quantitative differences in the proteasome‐generated antigenic peptides.