Genome-wide identification of RETINOBLASTOMA RELATED 1 binding sites in Arabidopsis reveals novel DNA damage regulators

PLoS Genet. 2018 Nov 30;14(11):e1007797. doi: 10.1371/journal.pgen.1007797. eCollection 2018 Nov.

Abstract

Retinoblastoma (pRb) is a multifunctional regulator, which was likely present in the last common ancestor of all eukaryotes. The Arabidopsis pRb homolog RETINOBLASTOMA RELATED 1 (RBR1), similar to its animal counterparts, controls not only cell proliferation but is also implicated in developmental decisions, stress responses and maintenance of genome integrity. Although most functions of pRb-type proteins involve chromatin association, a genome-wide understanding of RBR1 binding sites in Arabidopsis is still missing. Here, we present a plant chromatin immunoprecipitation protocol optimized for genome-wide studies of indirectly DNA-bound proteins like RBR1. Our analysis revealed binding of Arabidopsis RBR1 to approximately 1000 genes and roughly 500 transposable elements, preferentially MITES. The RBR1-decorated genes broadly overlap with previously identified targets of two major transcription factors controlling the cell cycle, i.e. E2F and MYB3R3 and represent a robust inventory of RBR1-targets in dividing cells. Consistently, enriched motifs in the RBR1-marked domains include sequences related to the E2F consensus site and the MSA-core element bound by MYB3R transcription factors. Following up a key role of RBR1 in DNA damage response, we performed a meta-analysis combining the information about the RBR1-binding sites with genome-wide expression studies under DNA stress. As a result, we present the identification and mutant characterization of three novel genes required for growth upon genotoxic stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / cytology
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism*
  • Binding Sites / genetics
  • Cell Cycle / genetics
  • Cell Proliferation / genetics
  • DNA Damage*
  • DNA Transposable Elements / genetics
  • DNA, Plant / genetics
  • DNA, Plant / metabolism
  • E2F Transcription Factors / genetics
  • E2F Transcription Factors / metabolism
  • Genome, Plant
  • Open Reading Frames
  • Trans-Activators / genetics
  • Trans-Activators / metabolism

Substances

  • Arabidopsis Proteins
  • DNA Transposable Elements
  • DNA, Plant
  • E2F Transcription Factors
  • RBR1 protein, Arabidopsis
  • Trans-Activators

Grants and funding

This work was funded by an European Research Area Network for Coordinating Action in Plant Sciences (ERA CAPS) grant (ALUCIDATE, LA 3685/1) of the Deutsche Forschungsgemeinschaft (DFG) to AS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.