title: Tip60 is a co-repressor for STAT3.
abstract: Tip60 (Tat-interactive protein, 60 kDa), a cellular protein with intrinsic histone acetyltransferase activity, is involved in DNA damage repair and apoptosis. Recent studies have suggested that Tip60 acts either as a co-activator or a co-repressor to modulate transcription. In this study, we demonstrate that Tip60 represses reporter gene expression when it is fused to the Gal4 DNA binding domain. We also show that Tip60 associates with histone deacetylase 7 (HDAC7) through its N-terminal zinc finger-containing region and that HDAC7 activity is required for the repressive effect of Tip60. Because endogenous Tip60 interacts with STAT3, we hypothesized that Tip60 might complex with STAT3 and HDAC7 and modulate STAT3-mediated trans-activation. Consistent with this hypothesis, the overexpression of Tip60 represses STAT3-driven reporter gene expression, which can be further potentiated by the co-transfection of HDAC7. Furthermore, interleukin-9-induced c-myc expression, which depends on STAT3 activity, is abrogated by exogenous expression of Tip60. This is the first demonstration of which Tip60 represses STAT3 activity in part through the recruitment of HDAC7.
authors.affiliation: Department of Pharmacology and Cancer Center, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Xiao
authors.forename: Jin
authors.initials: J
authors.lastname: Chung
authors.forename: Hung-Ying
authors.initials: HY
authors.lastname: Kao
authors.forename: Yu-Chung
authors.initials: YC
authors.lastname: Yang
mesh_terms: D000123:Acetyltransferases / Q000502:physiology*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects; D051548:Histone Acetyltransferases; D006655:Histone Deacetylases / Q000378:metabolism*; D006801:Humans; D016906:Interleukin-9 / Q000494:pharmacology; D000074443:Lysine Acetyltransferase 5; D011485:Protein Binding; D012097:Repressor Proteins / Q000502:physiology*; D050796:STAT3 Transcription Factor; D015534:Trans-Activators / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D016906:Interleukin-9; D012097:Repressor Proteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D000123:Acetyltransferases; D051548:Histone Acetyltransferases; C098489:KAT5 protein, human; D000074443:Lysine Acetyltransferase 5; C543273:HDAC7 protein, human; D006655:Histone Deacetylases