Fig. 2: IGF2BP family proteins bind to mRNA internal m⁷G.

a Protein mass spectrometry results with x-axis showing general binding on unmodified RNA and y-axis showing the binding of m⁷G over G. To calculate enrichment ratios for proteins identified by only one probe, 0.001 was added to all normalized spectral abundance factor (NSAF). The IGF2BP family proteins are highlighted in red. The reported reader QKI is marked in green. Top-ranked proteins are listed in Supplementary Data 1. b Western blot of HepG2 cell lysate in vitro pulldown using the m⁷G probe and G probe, respectively, with the estimation of enrichment folds plotted on the right. This experiment was repeated independently twice with similar results. The probe sequence is listed below the blots. c LC-MS/MS quantification of m⁷G/G levels showing enrichment of m⁷G after immunoprecipitation using antibodies against IGF2BPs. Mean ± SEM of three independent experiments. d Venn diagram of overlaps of transcripts that were bound by IGF2BPs and modified with m⁷G. e Left: metagene plot of IGF2BPs binding sites (not overlapped with m⁷G modified sites) (orange), m⁷G modified sites (not overlapped with IGF2BPs binding sites) (blue) and their overlapping sites (green). Right: Lollipop plot showing the overlaps between m⁷G and IGF2BPs quantified using Jaccard Index. f Venn diagram of overlaps of peaks that were bound by IGF2BPs and modified with m⁷G. g Proportion of m⁷G sites overlapping with IGF2BPs binding sites. m⁷G sites were categorized into groups based on m⁷G enrichment quantified as log₂FC(IP/Input). h Enrichment of m⁶A (left) and m⁷G (right) with IGF2BP1, IGF2BP2, and IGF2BP3 motifs, respectively, quantified with odds ratio. i Binding intensity of IGF2BP1, IGF2BP2, and IGF2BP3 at m⁷G sites and their flanking 500 bp, respectively. All source data are provided as a Source Data file.