title: Hepatitis B virus HBx peptide 116-138 and proteasome activator PA28 compete for binding to the proteasome alpha4/MC6 subunit.
abstract: PA28 is a modulator of the 20S proteasome. The PA28 binding sites on the 20S proteasome are still not well defined. Using yeast two-hybrid interaction assays and proteasome inactivation kinetics we provide evidence that the proteasome alpha4 subunit is one of the PA28 binding sites. This finding is supported by the observation that a hepatitis B virus X protein-derived polypeptide habouring the alpha4 proteasome subunit binding motif impairs the activation of 20S proteasomes by PA28.
authors.affiliation: Department of Food Chemistry and Preventive Nutrition, German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), Arthur-Scheunert-Allee 114-116, D-14558 Bergholz-Rehbrücke, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Stohwasser
authors.forename: Hermann-Georg
authors.initials: HG
authors.lastname: Holzhütter
authors.forename: Undine
authors.initials: U
authors.lastname: Lehmann
authors.forename: Peter
authors.initials: P
authors.lastname: Henklein
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kloetzel
mesh_terms: D000465:Algorithms; D000818:Animals; D001324:Autoantigens; D001667:Binding, Competitive; D015153:Blotting, Western; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D005982:Glutathione Transferase / Q000737:chemistry; D006515:Hepatitis B virus / Q000737:chemistry*; D007700:Kinetics; D051379:Mice; D009097:Multienzyme Complexes; D010446:Peptide Fragments / Q000096:biosynthesis / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000096:biosynthesis / Q000378:metabolism*; D014760:Viral Fusion Proteins / Q000302:isolation & purification; D054334:Viral Regulatory and Accessory Proteins; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D001324:Autoantigens; D017931:DNA Primers; D018076:DNA, Complementary; C099558:Ki antigen; D009097:Multienzyme Complexes; D010446:Peptide Fragments; D011506:Proteins; D016601:RNA-Binding Proteins; D015534:Trans-Activators; D014760:Viral Fusion Proteins; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein; D005982:Glutathione Transferase; D001616:beta-Galactosidase; C465641:PSMA6 protein, human; D046988:Proteasome Endopeptidase Complex