Proteasome isoforms exhibit only quantitative differences in cleavage and epitope generation.
Eur J Immunol
; 44(12): 3508-21, 2014 Dec.
Article
em En
| MEDLINE
| ID: mdl-25231383
ABSTRACT
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.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
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Antígenos de Histocompatibilidade Classe I
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Apresentação de Antígeno
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Complexo de Endopeptidases do Proteassoma
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Proteólise
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article