title: β5t-containing thymoproteasome: specific expression in thymic cortical epithelial cells and role in positive selection of CD8+ T cells.
abstract: Proteasomes are multisubunit proteolytic complexes that degrade cytoplasmic and nuclear proteins in eukaryotes. Proteasome-dependent proteolysis contributes to various cellular processes, including misfolded protein degradation, signal transduction, and antigen presentation. The thymoproteasome is a form of proteasome that contains the vertebrate-specific catalytic subunit β5t specifically expressed by cortical epithelial cells in the thymus. The thymoproteasome is essential for the positive selection of CD8+ T cells that carry an immunocompetent repertoire of antigen recognition specificity. Here we summarize the structure and expression of the thymoproteasome and discuss how it regulates the positive selection of CD8+ T cells.
authors.affiliation: Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima 770-8503, Japan. takahama@genome.tokushima-u.ac.jp
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Takahama
authors.forename: Kensuke
authors.initials: K
authors.lastname: Takada
authors.forename: Shigeo
authors.initials: S
authors.lastname: Murata
authors.forename: Keiji
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D017951:Antigen Presentation; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D004847:Epithelial Cells / Q000201:enzymology; D006801:Humans; D046988:Proteasome Endopeptidase Complex / Q000502:physiology*; D013950:Thymus Gland / Q000201:enzymology*
chemical_list: C520308:PSMB11 protein, human; D046988:Proteasome Endopeptidase Complex