Figure 3.

IGF2BP1 destabilizes AJs in a SRC-dependent manner. (A, B) Turnover of indicated proteins was determined by blocking protein synthesis with Emetine (100 µM) by Western blotting upon IGF2BP1 (siI1) and control (siC) knockdown. GAPDH and VCL served as loading controls to determine protein abundance relative to input levels. (C,D) Immunostainings of ES-2 cells treated with PP2 (1 µM) or DMSO for 48 h using indicated antibodies (C). Dashed box indicates enlargement. Scale bars 25 µm. The AJ/cytoplasmic ratio of CDH2 and CTNNB1 is shown by box plots (D). (E, F) Western blot analyses of indicated proteins in ES-2 cells upon IGF2BP1 depletion (E) and OVCAR-3 cells (F) with GFP or GFP-IGF2BP1 (G-I1) over-expression. SRC activity, indicated by Y419 phosphorylation, was normalized to SRC expression, as depicted under the lanes. VCL served as loading control. Error bars show SD determined in three independent experiments. Statistical significance was tested by Student’s T-test. *, p < 0.05; ***, p < 0.001