cDNA Cloning and Interferon γ Down-Regulation of Proteasomal Subunits X and Y

• Published in: Science (American Association for the Advancement of Science) Vol. 265; no. 5176; pp. 1231 - 1234
• Main Authors: Akiyama, Kin-Ya, Yokota, Kim-ya, Kagawa, Susumu, Shimbara, Naoki, Tamura, Tomohiro, Akioka, Hiroshi, Nothwang, Hans G., Noda, Chiseko, Tanaka, Keiji, Ichihara, Akira
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 26-08-1994; American Association for the Advancement of Science
• Subjects: Amino Acid Sequence; Amino acids; Analysis of the immune response. Humoral and cellular immunity; Antigens; Base Sequence; Biological and medical sciences; cDNA; CDNA libraries; Cloning, Molecular; Complementary DNA; Cysteine Endopeptidases; DNA, Complementary - genetics; Down-Regulation; Endopeptidases - chemistry; Endopeptidases - genetics; Fundamental and applied biological sciences. Psychology; Fundamental immunology; gamma -interferon; gene expression; genes; Hep G2 cells; Human immunogenetics; Humans; Immunobiology; Interferon-gamma - pharmacology; Interferons; Lymphokines, interleukins ( function, expression); Major Histocompatibility Complex; man; Messenger RNA; Molecular Sequence Data; Molecules; Multienzyme Complexes; nucleotide sequence; Polymerase chain reaction; prediction; Proteasome Endopeptidase Complex; Proteins - chemistry; Proteins - genetics; Proteins - metabolism; proteosomes; Regulatory factors and their cellular receptors; Sequence Homology, Amino Acid; Tumor Cells, Cultured; X subunit; Y subunit; Human; Multicatalytic endopeptidase complex; Enzyme; Cytokine; Sequence alignment; Gene expression; Subunit; Regulation(control); Hydrolases; Molecular cloning; Proteinases; Aminoacid sequence; Structural analysis; Gamma interferon
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.8066462

Proteasomes are the proteolytic complex responsible for major histocompatibility complex (MHC) class I-restricted antigen presentation. Interferon γ treatment increases expression of MHC-encoded LMP2 and LMP7 subunits of the proteasome and decreases expression of two proteasome subunits, named X and Y, which alters the proteolytic specificity of proteasomes. Molecular cloning of complementary DNAs encoding X and Y showed that their proteins are proteasomal subunits with high amino acid similarity to LMP7 and LMP2, respectively. Thus, interferon γ may induce subunit replacements of X and Y by LMP7 and LMP2, respectively, producing proteasomes perhaps more appropriate for the immunological processing of endogenous antigens.