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

PLoS One. 2012;7(8):e44125. doi: 10.1371/journal.pone.0044125. Epub 2012 Aug 28.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites / genetics
  • Cell Line
  • Cell Nucleus / genetics*
  • Cell Nucleus / metabolism
  • Cells, Cultured
  • Gene Expression
  • Genes, Reporter
  • Mice
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases / genetics*
  • Poly(ADP-ribose) Polymerases / metabolism
  • Promoter Regions, Genetic*
  • Protein Binding / genetics
  • Transfection
  • YY1 Transcription Factor / genetics*
  • YY1 Transcription Factor / metabolism

Substances

  • YY1 Transcription Factor
  • Yy1 protein, mouse
  • Parp1 protein, mouse
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases

Grant support

This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, Project No. 173020. Work in the laboratories of J.B. at HZI and at MHH was supported by the Excellence Initiative REBIRTH (Regenerative Biology to Reconstructive Therapy), the SFB 738 (Optimierung konventioneller und innovativer Transplantate), and a ReGene (Regenerative Medicine and Biology) Grant from the Bundesministerium für Bildung und Forschung. M.V.’s work in the lab of J.B. was enabled by the Alexander von Humboldt Foundation Grant (Roman Herzog stipend IV-SER/1121681 STP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.