Fig. 4

G4s are hubs for the recruitment TFs to enhance transcription. Throughout panels a–c gene endogenous G4 in promoters accessible in open chromatin (− 1 kb upstream TSS, DHS positive) are colored in green whereas promoters lacking an endogenous G4 are represented in gray. a Endogenous G4s mark genomic regions that are highly occupied by TFs. Proportion of G4s overlapping with multiple different TFs in K562 cells (top) and HepG2 cells (bottom). b Distributions of transcript levels split by the number of TFs binding at G4s in promoters or at promoters lacking G4s in K562 (top) and HepG2 cells (bottom) (unpaired Wilcoxon test). The number of cases (shown in brackets) for higher TF occupancy is substantially higher for G4s. c The average transcriptional output (displayed in transcripts per million (TPM), log₁₀ scale) is compared for genes with and without endogenous G4s in promoters in K562 (left) and HepG2 cells (right) (unpaired Wilcoxon test). d A model for how endogenous G4s can enhance occupancy by multiple TFs at promoters: (i) Repressed promoters are unoccupied by TFs. (ii) Double-stranded DNA consensus binding sites recruit particular TFs to promoters resulting in active transcription. (iii) G4s can recruit numerous different TFs causing even more actively transcribed genes