Fig. 3: GSK3β stabilizes SIRT7 by phosphorylation-dependent decoupling of UBR5.

a, b Immunoblots showing SIRT7 levels in MDA-231 (a) and HeLa cells (b) following GSK3β knockdown or overexpression. Scr, scrambled siRNA; #1 and #2, two independent siRNAs targeting GSK3β mRNA. c–j Immunoblots showing SIRT7 levels in MDA-231 (c–f) and HeLa cells (g–j) following the indicated treatments (c, e, g, i); the related quantifications (d, f, h, j) were based on three independent experiments; LiCl, 10 mM; MG132, 10 µM. k, l Immunoblots showing SIRT7 levels in CHX (50 µg/ml) chase assay of HEK293 cells transfected with SIRT7-WT/-2A/-2E (k) and the related quantification (l) was based on three independent experiments. m–p Immunoblots showing SIRT7 ubiquitination levels in HEK293 cells following transfection with the indicated plasmids/siRNAs. K63R or K48R represented the corresponding lysine was replaced by arginine on ubiquitin, respectively. q Binding of endogenous SIRT7 to UBR5 was assessed in cells with or without GSK3β knockdown. r Binding of SIRT7-WT and the indicated mutants with UBR5 was evaluated in HEK293 cells. Data represent means ± SEM (d, f, h, j, l). P values were determined by two-way ANOVA analysis. Representative results were observed from at least three independent experiments. Source data are provided as a Source Data file.