Topoisomerases facilitate transcription of long genes linked to autism

Nature. 2013 Sep 5;501(7465):58-62. doi: 10.1038/nature12504. Epub 2013 Aug 28.

Abstract

Topoisomerases are expressed throughout the developing and adult brain and are mutated in some individuals with autism spectrum disorder (ASD). However, how topoisomerases are mechanistically connected to ASD is unknown. Here we find that topotecan, a topoisomerase 1 (TOP1) inhibitor, dose-dependently reduces the expression of extremely long genes in mouse and human neurons, including nearly all genes that are longer than 200 kilobases. Expression of long genes is also reduced after knockdown of Top1 or Top2b in neurons, highlighting that both enzymes are required for full expression of long genes. By mapping RNA polymerase II density genome-wide in neurons, we found that this length-dependent effect on gene expression was due to impaired transcription elongation. Interestingly, many high-confidence ASD candidate genes are exceptionally long and were reduced in expression after TOP1 inhibition. Our findings suggest that chemicals and genetic mutations that impair topoisomerases could commonly contribute to ASD and other neurodevelopmental disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autistic Disorder / genetics*
  • DNA Topoisomerases, Type I / deficiency
  • DNA Topoisomerases, Type I / metabolism*
  • DNA Topoisomerases, Type II / deficiency
  • DNA Topoisomerases, Type II / metabolism
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / deficiency
  • DNA-Binding Proteins / metabolism
  • Gene Knockdown Techniques
  • Genomic Imprinting / genetics
  • Humans
  • Mice
  • Mutation / genetics
  • Poly-ADP-Ribose Binding Proteins
  • RNA Polymerase II / metabolism
  • Synapses / metabolism
  • Topoisomerase Inhibitors / pharmacology
  • Topotecan / pharmacology
  • Transcription Elongation, Genetic* / drug effects

Substances

  • DNA-Binding Proteins
  • Poly-ADP-Ribose Binding Proteins
  • Topoisomerase Inhibitors
  • Topotecan
  • RNA Polymerase II
  • DNA Topoisomerases, Type I
  • DNA Topoisomerases, Type II
  • TOP2B protein, human
  • Top2b protein, mouse

Associated data

  • GEO/GSE43900