Fig. 6.
P182–195 induces proteasomal degradation of β-catenin. a Immunofluorescence staining of endogenous β-catenin (green) in SW480 and SW480 AXIN2 knockout cells co-transfected with P182–195 or its QV-PS mutated analog together with mScarlet-tubulin (red) to visualize transfected cells. Scale bar: 20 µm. b, c Quantification of nuclear β-catenin (b) or mScarlet (c) fluorescence intensities in individual cells of four independent experiments as in a. Results are mean ± SEM (n = 80); ***p < 0.001 (Student’s t-test). Data distribution is shown in Supplementary Fig. 10. d, e Western blotting for GFP and α-tubulin (loading control) in lysates of DLD1 (d) or HEK293T cells (e) transfected with indicated constructs, which were untreated or treated with the proteasome inhibitor MG132 (DLD1: 10 µM for 6 h; HEK293T: 2.5 µM for 2 h). Given nanograms (ng) of the peptide refer to the transfection of a 12 well. f Western blotting for GFP and HA in lysates (Input) of HEK293T cells transfected with indicated constructs, and after precipitation of HA-ubiquitin conjugated proteins from these lysates (IP α HA). Arrowheads point to polyubiquitinated GFP-β-catenin. HA blots show similar overall ubiquitination (Input) and similar precipitation of ubiquitinated proteins (IP) in both samples. Source data are provided as a Source Data file