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Fig. 8 TRIP12 promotes the interaction of BRG1 with β-catenin.A HEK293FT cells were transfected with nontargeting (siNT) control or two pooled TRIP12 siRNAs and incubated in the presence or absence of Wnt3a. Endogenous BRG1 was immunoprecipitated with a BRG1 antibody. IgG was used as a negative control. Coimmunoprecipitated, endogenous β-catenin was detected by immunoblotting. *indicates a nonspecific band. B HEK293FT cells were transfected with wild-type or catalytic dead TRIP12 as indicated. Endogenous β-catenin was immunoprecipitated with a β-catenin antibody. IgG was used as a negative control. Coimmunoprecipitated, endogenous BRG1 was detected by immunoblotting. Immunoblots are representative of at least three independent experiments. α-tubulin is a loading control. *indicates a nonspecific band. C HiBiT-tagged BRG1 was co-overexpressed with LgBiT-tagged β-catenin. When the two proteins are in close proximity, the HiBiT and LgBiT proteins interact and form a functional NanoBit luciferase enzyme. Addition of the HiBiT substrate results in an enzymatic reaction that produces a light signal, which was used as a readout for the interaction between BRG1 and β-catenin. HEK293FT cells were transfected as indicated and TRIP12 was knocked down (D) or overexpressed (E). Cells were treated with or without Wnt3a as indicated and luminescence was quantified as relative light units (RLU). Cell extracts were immunoblotted for TRIP12, β-catenin-V5-LgBiT, and BRG1-HA-HiBiT. *indicates a nonspecific band. α-tubulin is a loading control. Graphs show mean ± SEM of luminescence normalized to cell number. Significance was assessed using the one-way ANOVA with Tukey’s test. p-value for NT versus TRIP12 is >0.9999 (–), 0.0401 (+), 0.0297 (++), and <0.0001 (+++). p-value for myc-TRIP12 + Wnt3a versus control is 0.0002, versus myc-TRIP12 is 0.0473, and versus control + Wnt3a is 0.0369. All HiBiT results and immunoblots are representative of at least three independent experiments. n = 3–4 wells of cells per treatment group per experiment. F Upon Wnt pathway activation, TRIP12 ubiquitylates BRG1 and promotes BRG1 association with β-catenin. *p < 0.05, ***p < 0.001, ****p < 0.0001, p ≥ 0.05 is not significant (ns). Source data are provided in Source Data file.