Fig. 8

SIRT7 and SIRT1 regulate OSX transactivation activity through lysine deacylation. a Co-immunoprecipitation assay to assess the interaction between HA-SIRT1 and GAL4DBD-OSX (27–270) in HEK293T cells. b Effect of SIRT7 and SIRT1 overexpression on propionylation of OSX. Sirt7 KO MEF were transfected with the 3× HA-OSX expression plasmid, as well as the SIRT7 or SIRT1 expression plasmid, followed by treatment with 50 mM Na-Prop for 16 h. Then propionylation of OSX was assessed by immunoprecipitation and WB. c Effect of SIRT7 and SIRT1 overexpression on transactivation activity of OSX. Sirt7 KO MEF were transfected with the 3× HA-OSX expression plasmid, as well as the SIRT7 or SIRT1 expression plasmid, followed by treatment with 10 mM Na-Prop for 24 h. Then the cells were transfected with the Col1a1 enhancer/promoter-driven luciferase reporter plasmid, and the reporter assay was performed after 24 h (n = 6 each). d Effect of SIRT1 on transactivation activity of the OSX (K368R) mutant. Sirt7 KO MEF were transfected with the 3× HA-OSX or 3× HA-OSX (K368R) expression plasmid, as well as the SIRT1 expression plasmid, followed by treatment with 30 mM Na-Prop for 24 h. Then the cells were transfected with the Col1a1 enhancer/promoter-driven luciferase reporter plasmid, and the reporter assay was performed after 24 h (n = 6 each). WB, western blotting; IP, immunoprecipitation. Data are shown as the mean ± SEM. Statistical significance was determined by Student’s t-test. *p < 0.05 vs. without SIRT1 and SIRT7 (c)