Fig. 4.

Dyrk1b downregulates Wbp2 protein abundance. (a) Volcano plot of differentially expressed proteins between livers of Ad-EGFP (n = 3) and Ad-Dyrk1b (n = 4) female mice. (b) Heatmap of the top 20 differentially expressed proteins between livers of Ad-EGFP (n = 3) and Ad-Dyrk1b (n = 4) female mice. (c) The top 30 enriched KEGG pathways of differentially expressed proteins between livers of Ad-EGFP (n = 3) and Ad-Dyrk1b (n = 4) female mice. (d–e) Western blot and densitometry quantification of Wbp2 in livers of Ad-EGFP (n = 4) and Ad-Dyrk1b (n = 8) female mice. Unpaired Student's t-test (two-sided) was performed for Fig. 4e. (f–g) Western blot and densitometry quantification of Wbp2 in Hepa1-6 cells infected with Ad-EGFP or Ad-Dyrk1b (n = 6). Unpaired Student's t-test (two-sided) was performed for Fig. 4g. (h–i) Western blot and densitometry quantification of Wbp2 in Hepa1-6 cells infected with adenovirus expressing wild-type or kinase-defective Dyrk1b (n = 4). One-way ANOVA with Tukey's post-hoc test was performed for Fig. 4i. (j–k) Representative Western blot and densitometry quantification of Wbp2 in Hepa1-6 cells infected with Ad-EGFP or Ad-Dyrk1b and treated with cycloheximide (20 μg/ml) for the indicated time points (n = 4). Unpaired Student's t-test (two-sided) was performed for Fig. 4k. (l–m) Western blot and densitometry quantification of Wbp2 in Hepa1-6 cells infected with Ad-EGFP or Ad-Dyrk1b in the absence or presence of MG132 (5 μM, 4 h) (n = 3). Two-way ANOVA with Tukey's post-hoc test was performed for Fig. 4m. (n) HA-tagged wild-type or kinase-defective Dyrk1b was expressed in Hepa1-6 cells together with Wbp2-Flag and Ub-Myc. At 45 h post-transfection, cells were treated with MG132 (20 μM) for 3 h and levels of Wbp2 ubiquitylation were evaluated by immunoprecipitation of Wbp2 using anti-Flag antibody followed by anti-Myc immunoblotting. *P < 0.05, **P < 0.01, ***P < 0.001, n.s., not significant.