RPA1 binding to NRF2 switches ARE-dependent transcriptional activation to ARE-NRE-dependent repression

Proc Natl Acad Sci U S A. 2018 Oct 30;115(44):E10352-E10361. doi: 10.1073/pnas.1812125115. Epub 2018 Oct 11.

Abstract

NRF2 regulates cellular redox homeostasis, metabolic balance, and proteostasis by forming a dimer with small musculoaponeurotic fibrosarcoma proteins (sMAFs) and binding to antioxidant response elements (AREs) to activate target gene transcription. In contrast, NRF2-ARE-dependent transcriptional repression is unreported. Here, we describe NRF2-mediated gene repression via a specific seven-nucleotide sequence flanking the ARE, which we term the NRF2-replication protein A1 (RPA1) element (NRE). Mechanistically, RPA1 competes with sMAF for NRF2 binding, followed by interaction of NRF2-RPA1 with the ARE-NRE and eduction of promoter activity. Genome-wide in silico and RNA-seq analyses revealed this NRF2-RPA1-ARE-NRE complex mediates negative regulation of many genes with diverse functions, indicating that this mechanism is a fundamental cellular process. Notably, repression of MYLK, which encodes the nonmuscle myosin light chain kinase, by the NRF2-RPA1-ARE-NRE complex disrupts vascular integrity in preclinical inflammatory lung injury models, illustrating the translational significance of NRF2-mediated transcriptional repression. Our findings reveal a gene-suppressive function of NRF2 and a subset of negatively regulated NRF2 target genes, underscoring the broad impact of NRF2 in physiological and pathological settings.

Keywords: MYLK/MLCK; NRF2; RPA1; acute lung injury; transcriptional regulation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • A549 Cells
  • Animals
  • Cell Line
  • Cell Line, Tumor
  • DNA-Binding Proteins / genetics
  • Genome / genetics
  • Humans
  • Mice
  • NF-E2-Related Factor 2 / genetics*
  • Promoter Regions, Genetic / genetics
  • Replication Protein A / genetics*
  • Repressor Proteins / genetics*
  • Response Elements / genetics
  • Transcription, Genetic / genetics*
  • Transcriptional Activation / genetics*

Substances

  • DNA-Binding Proteins
  • NF-E2-Related Factor 2
  • Replication Protein A
  • Repressor Proteins