Transcriptome-wide identification of transient RNA G-quadruplexes in human cells

We report here on G4RP-seq, which comprises of a cross-linking step, followed by chemical-affinity capture with the G4-specific small-molecule, BioTASQ and target identification using sequencing. This allows for capturing global snapshots of relative average levels of transiently folded G4-RNAs. We observed widespread G4-RNA targets indicative of transient G4 formation in several RNA entities in living human cells. G4RP-seq has also demonstrated that G4-stabilizing ligands (BRACO-19 and RHPS4) can change the G4 transcriptomic landscape, most notably in long non-coding RNAs. G4RP-seq thus provides a proof-of-principle for studying the G4-RNA landscape, as well as new ways of considering the mechanisms underlying G4-RNA formation and the activity of G4-stabilizing ligands. Two BioTASQ-enriched samples and one input control for three different conditions (Untreated, BRACO-19-treated, and RHPS4-treated) in MCF7 cells