Fig. 4

CHK1 inhibition causes a decrease in the steady-state levels of STAU2 protein. a hTERT-RPE1 and HCT116 cells were incubated in the presence of the CHK1 inhibitor PF47 (20 μM) for 8.5 h. Cell extracts were analyzed by Western blotting. The vehicle DMSO was used as control and β-actin as a loading control. PARP1 cleavage was used as a measure of apoptosis. Quantification of STAU2 protein levels is indicated below the blots. Western blots are representative of at least three independently performed experiments that gave similar results. b Cells were incubated in the presence of CHK1 inhibitor (PF47 20 μM) for 6.5 h. STAU2 protein expression was analyzed by western blotting, while STAU2 mRNA levels were quantified by RT-qPCR. The ratio of STAU2 (protein or mRNA) on actin (protein or mRNA, respectively) in DMSO-treated cells was fixed to 1. n = 3. ** p-value ≤0.01. One sample t-test. c WT and STAU2-KO A4 hTERT-RPE1 cells were analyzed by Western blotting for expression of STAU2, CHK1 and PARP1. Actin was used as a loading control. d WT and STAU2-KO A4 hTERT-RPE1 cells were treated with the pan-caspase inhibitor emricasan. Cell proliferation using growth curve assays was quantified every day using the crystal violet retention assay. Statistic: Dunnett’s multiple comparisons (e) Dotplot representation of protein abundance in proximity to STAU2 in the presence or absence of the CHK1 inhibitor PF47. Color range indicates peptide abundance and the size of circles their relative abundance