Fig. 4. SIRT6 interacts physically with Runx2/Osx and is recruited to their target promoters.
(A) Western blots showing expression of SIRT6, Runx2, and Osx in NIH3T3 cells with retroviral infection of SIRT6 and transient transfection of Runx2 or Osx. αTubulin was used as a loading control. (B) SIRT6 binding to Runx2 and Osx, as determined by western blots of SIRT6 or Flag antibody immunoprecipitates from SIRT6 WT overexpressing cells with Flag-Runx2 or Flag-Osx. IgG antibody was used as a negative control for IP assay. The arrow indicates Runx2 and Osx expression. (C) ChiP analysis to detect SIRT6 at the indicated promoters in SIRT6 overexpressing MC3T3-E1 cells with or without BMP-2 treatment. Data represented means ± S.E. of three experiments in triplicate. *, p < 0.01. (D). ChiP analysis to detect endogenous SIRT6 at the indicated promoters in osteoblasts with BMP-2 stimulation (24h).