MYC mediates mRNA cap methylation of Wnt/β-catenin signaling pathway transcripts through an interaction between NuA4 and TFIIH. (A) Immunoprecipitation of XPB, MYC, TIP60, CDK7, or MRG15 from HEK293T cells overexpressing MYC. Co-immunoprecipitated proteins detected using Western blot. (B) ChIP for phospho-S5 RNA Pol II was performed in IMECs where TIP60, MRG15, or MYC were depleted using siRNA. qPCR performed to detect levels of each factor at GSK3B and APC promoters (normalized to input, ACTB control) (n=3, biological). (C) Western blot to detect global phospho-S5 levels following depletion of TIP60, MRG15, or MYC. Error bars indicate SEM and asterisks indicate significance (*p < 0.05, **p < 0.01, ***p < 0.001).