A G-quadruplex structure within the 5'-UTR of TRF2 mRNA represses translation in human cells

Nucleic Acids Res. 2010 Nov;38(20):7187-98. doi: 10.1093/nar/gkq563. Epub 2010 Jun 22.

Abstract

Telomeres protect chromosome ends from being recognized as double-stranded breaks. Telomeric function is ensured by the shelterin complex in which TRF2 protein is an essential player. The G-rich strand of telomere DNA can fold into G-quadruplex (G4) structure. Small molecules stabilizing G4 structures, named G4 ligands, have been shown to alter telomeric functions in human cells. In this study, we show that a guanine-rich RNA sequence located in the 5'-UTR region of the TRF2 mRNA (hereafter 91TRF2G) is capable of forming a stable quadruplex that causes a 2.8-fold decrease in the translation of a reporter gene in human cells, as compared to a mutant 5'-UTR unable to fold into G4. We also demonstrate that several highly selective G4 ligands, the pyridine dicarboxamide derivative 360A and bisquinolinium compounds Phen-DC(3) and Phen-DC(6), are able to bind the 91TRF2G:RNA sequence and to modulate TRF2 protein translation in vitro. Since the naturally occurring 5'-UTR TRF2:RNA G4 element was used here, which is conserved in several vertebrate orthologs, the present data substantiate a potential translational mechanism mediated by a G4 RNA motif for the downregulation of TRF2 expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5' Untranslated Regions*
  • Base Sequence
  • Cell Line
  • G-Quadruplexes*
  • Gene Expression Regulation
  • Genes, Reporter
  • Green Fluorescent Proteins / analysis
  • Green Fluorescent Proteins / genetics
  • Humans
  • Ligands
  • Molecular Sequence Data
  • Protein Biosynthesis*
  • RNA Stability
  • Regulatory Sequences, Ribonucleic Acid*
  • Telomeric Repeat Binding Protein 2 / genetics*

Substances

  • 5' Untranslated Regions
  • Ligands
  • Regulatory Sequences, Ribonucleic Acid
  • TERF2 protein, human
  • Telomeric Repeat Binding Protein 2
  • Green Fluorescent Proteins