title: YY1-binding sites provide central switch functions in the PARP-1 gene expression network.
abstract: Evidence is presented for the involvement of the interplay between transcription factor Yin Yang 1 (YY1) and poly(ADP-ribose) polymerase-1 (PARP-1) in the regulation of mouse PARP-1 gene (muPARP-1) promoter activity. We identified potential YY1 binding motifs (BM) at seven positions in the muPARP-1 core-promoter (-574/+200). Binding of YY1 was observed by the electrophoretic supershift assay using anti-YY1 antibody and linearized or supercoiled forms of plasmids bearing the core promoter, as well as with 30 bp oligonucleotide probes containing the individual YY1 binding motifs and four muPARP-1 promoter fragments. We detected YY1 binding to BM1 (-587/-558), BM4 (-348/-319) and a very prominent association with BM7 (+86/+115). Inspection of BM7 reveals overlap of the muPARP-1 translation start site with the Kozak sequence and YY1 and PARP-1 recognition sites. Site-directed mutagenesis of the YY1 and PARP-1 core motifs eliminated protein binding and showed that YY1 mediates PARP-1 binding next to the Kozak sequence. Transfection experiments with a reporter gene under the control of the muPARP-1 promoter revealed that YY1 binding to BM1 and BM4 independently repressed the promoter. Mutations at these sites prevented YY1 binding, allowing for increased reporter gene activity. In PARP-1 knockout cells subjected to PARP-1 overexpression, effects similar to YY1 became apparent; over expression of YY1 and PARP-1 revealed their synergistic action. Together with our previous findings these results expand the PARP-1 autoregulatory loop principle by YY1 actions, implying rigid limitation of muPARP-1 expression. The joint actions of PARP-1 and YY1 emerge as important contributions to cell homeostasis.
authors.affiliation: Helmholtz Centre for Infection Research/Epigenetic Regulation, Braunschweig, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Doetsch
authors.forename: Angela
authors.initials: A
authors.lastname: Gluch
authors.forename: Goran
authors.initials: G
authors.lastname: Poznanović
authors.forename: Juergen
authors.initials: J
authors.lastname: Bode
authors.forename: Melita
authors.initials: M
authors.lastname: Vidaković
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D015870:Gene Expression; D017930:Genes, Reporter; D051379:Mice; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000235:genetics; D014162:Transfection; D050986:YY1 Transcription Factor / Q000235:genetics* / Q000378:metabolism
chemical_list: D050986:YY1 Transcription Factor; C494699:Yy1 protein, mouse; C499321:Parp1 protein, mouse; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases