Genome-wide mapping of endogenous G-quadruplex DNA structures by chromatin immunoprecipitation and high-throughput sequencing

Nat Protoc. 2018 Mar;13(3):551-564. doi: 10.1038/nprot.2017.150. Epub 2018 Feb 22.

Abstract

G-rich DNA sequences can form four-stranded G-quadruplex (G4) secondary structures and are linked to fundamental biological processes such as transcription, replication and telomere maintenance. G4s are also implicated in promoting genome instability, cancer and other diseases. Here, we describe a detailed G4 ChIP-seq method that robustly enables the determination of G4 structure formation genome-wide in chromatin. This protocol adapts traditional ChIP-seq for the detection of DNA secondary structures through the use of a G4-structure-specific single-chain antibody with refinements in chromatin immunoprecipitation followed by high-throughput sequencing. This technology does not require expression of the G4 antibody in situ, enabling broad applicability to theoretically all chromatin sources. Beginning with chromatin isolation and antibody preparation, the entire protocol can be completed in <1 week, including basic computational analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Chromatin
  • Chromatin Immunoprecipitation / methods*
  • Chromosome Mapping / methods*
  • Chromosome Structures / genetics
  • Chromosome Structures / physiology
  • DNA
  • DNA Replication
  • G-Quadruplexes*
  • Genome-Wide Association Study
  • Genomic Instability
  • Guanosine / analysis
  • High-Throughput Nucleotide Sequencing / methods
  • Humans

Substances

  • Chromatin
  • Guanosine
  • DNA