eLife (Feb 2020)

Small-molecule G-quadruplex stabilizers reveal a novel pathway of autophagy regulation in neurons

  • Jose F Moruno-Manchon,
  • Pauline Lejault,
  • Yaoxuan Wang,
  • Brenna McCauley,
  • Pedram Honarpisheh,
  • Diego A Morales Scheihing,
  • Shivani Singh,
  • Weiwei Dang,
  • Nayun Kim,
  • Akihiko Urayama,
  • Liang Zhu,
  • David Monchaud,
  • Louise D McCullough,
  • Andrey S Tsvetkov

DOI
https://doi.org/10.7554/eLife.52283
Journal volume & issue
Vol. 9

Abstract

Read online

Guanine-rich DNA sequences can fold into four-stranded G-quadruplex (G4-DNA) structures. G4-DNA regulates replication and transcription, at least in cancer cells. Here, we demonstrate that, in neurons, pharmacologically stabilizing G4-DNA with G4 ligands strongly downregulates the Atg7 gene. Atg7 is a critical gene for the initiation of autophagy that exhibits decreased transcription with aging. Using an in vitro assay, we show that a putative G-quadruplex-forming sequence (PQFS) in the first intron of the Atg7 gene folds into a G4. An antibody specific to G4-DNA and the G4-DNA-binding protein PC4 bind to the Atg7 PQFS. Mice treated with a G4 stabilizer develop memory deficits. Brain samples from aged mice contain G4-DNA structures that are absent in brain samples from young mice. Overexpressing the G4-DNA helicase Pif1 in neurons exposed to the G4 stabilizer improves phenotypes associated with G4-DNA stabilization. Our findings indicate that G4-DNA is a novel pathway for regulating autophagy in neurons.

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