YY1-binding sites provide central switch functions in the PARP-1 gene expression network

• Published in: PloS one Vol. 7; no. 8; p. e44125
• Main Authors: Doetsch, Martina, Gluch, Angela, Poznanović, Goran, Bode, Juergen, Vidaković, Melita
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 28.08.2012; Public Library of Science (PLoS)
• Subjects: Adenosine diphosphate; Animals; Apoptosis; Binding sites; Binding Sites - genetics; Biochemistry; Biology; Cancer; Cell Line; Cell Nucleus - genetics; Cell Nucleus - metabolism; Cells, Cultured; Deoxyribonucleic acid; DNA; DNA methylation; DNA repair; Enzymes; Epigenetics; Gene Expression; Genes, Reporter; Genetic aspects; Homeostasis; Infections; Inspection; Laboratories; Mice; Molecular biology; Mutagenesis; Mutation; Oligonucleotides; Physiological aspects; Plasmids; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose); Poly(ADP-ribose) polymerase; Poly(ADP-ribose) Polymerases - genetics; Poly(ADP-ribose) Polymerases - metabolism; Promoter Regions, Genetic; Protein binding; Protein Binding - genetics; Proteins; Reporter gene; Ribose; RNA polymerase; Rodents; Site-directed mutagenesis; Transcription factors; Transfection; YY1 protein; YY1 Transcription Factor - genetics; YY1 Transcription Factor - metabolism; Germany; Serbia
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0044125

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.