title: Human immunodeficiency virus-1 Tat protein interacts with distinct proteasomal alpha and beta subunits.
abstract: The human immunodeficiency virus-1 (HIV-1) Tat protein was previously reported to compete the association of PA28 regulator with the alpha rings of the 20S proteasome and to inhibit its peptidase activity. However, the distinct interaction sites within the proteasome complex remained to be determined. Here we show that HIV-1 Tat binds to alpha4 and alpha7, six beta subunits of the constitutive 20S proteasome and the interferon-gamma-inducible subunits beta2i and beta5i. A Tat-proteasome interaction can also be demonstrated in vivo and leads to inhibition of proteasomal activity. This indicates that Tat can modulate or interfere with cellular proteasome function by specific interaction with distinct proteasomal subunits.
authors.affiliation: Humboldt Universität zu Berlin, Universitätsklinikum Charité, Institut für Biochemie, Germany.
authors.forename: G Sébastien
authors.initials: GS
authors.lastname: Apcher
authors.forename: Sylvia
authors.initials: S
authors.lastname: Heink
authors.forename: Daniela
authors.initials: D
authors.lastname: Zantopf
authors.forename: Peter-M
authors.initials: PM
authors.lastname: Kloetzel
authors.forename: Hans-P
authors.initials: HP
authors.lastname: Schmid
authors.forename: R John
authors.initials: RJ
authors.lastname: Mayer
authors.forename: Elke
authors.initials: E
authors.lastname: Krüger
mesh_terms: D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism; D015696:Gene Products, tat / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism*; D011233:Precipitin Tests; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015853:Cysteine Proteinase Inhibitors; D015696:Gene Products, tat; D009097:Multienzyme Complexes; D021122:Protein Subunits; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex