Characterization of the mouse PA28 activator complex gene family: complete organizations of the three member genes and a physical map of the approximately 150-kb region containing the alpha- and beta-subunit genes.
The proteasome is a multisubunit protease responsible for the generation of peptides loaded onto MHC class I molecules. Recent evidence indicates that binding of an IFN-gamma-inducible PA28 activator complex to the 20S proteasome enhances the generation of class I binding peptides. The alpha- and beta-subunits, which constitute the PA28 activator complex in the form of an (alphabeta)3 heterohexamer, show significant amino acid sequence similarity to a protein, designated Ki or the gamma-subunit, that is capable of binding to the 20S proteasome. In this study, we describe the complete nucleotide sequences of the mouse genes, Psme1, Psme2, and Psme3, coding for the alpha-, beta-, and gamma-subunits, respectively. The overall exon-intron organizations of the three Psme genes are virtually identical, thus providing evidence that they are descended from a single ancestral gene. The promoter regions of the Psme1 and Psme2 genes contain sequence motifs that qualify as IFN-stimulated response elements, consistent with the observation that their expression is induced strongly by IFN-gamma. The Psme1 and Psme2 genes are located approximately 6 kb apart with their 3'-ends pointing toward each other on bands C2 to D1 of mouse chromosome 14, supporting the idea that they emerged by tandem duplication.
Kohda
K
K
Department of Biochemistry, Hokkaido University School of Medicine, Sapporo, Japan.
Ishibashi
T
T
Shimbara
N
N
Tanaka
K
K
Matsuda
Y
Y
Kasahara
M
M
D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D001483:Base Sequence; D002874:Chromosome Mapping; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000502:physiology; D004789:Enzyme Activation; D015395:Histocompatibility Antigens Class I; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics* / Q000502:physiology; D011401:Promoter Regions, Genetic; D046988:Proteasome Endopeptidase Complex; D011506:Proteins; D012091:Repetitive Sequences, Nucleic Acid
D015395:Histocompatibility Antigens Class I; D009097:Multienzyme Complexes; D011506:Proteins; D007371:Interferon-gamma; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; C486213:Psme1 protein, mouse; C486214:Psme2 protein, mouse