SIRT1-mediated deacetylation increases Foxp3 poly-ubiquitination.

<p>(<b>A</b>) HEK293 cells ectopically expressing HA-Foxp3 were transfected with Flag-SIRT1. Cell lysates were prepared and HA-Foxp3 was immunoprecipitated. Acetylated Foxp3 was visualized by Western blotting using anti-acetylated lysine antibodies. (<b>B</b>) Analysis of Foxp3 acetylation after treatment with 20 mM nicotinamide (NAM) for 16 hours as in (<b>A</b>). (<b>C</b>) Cells were transfected with Flag-Foxp3 and treated with 20 mM NAM (for three hours), Foxp3 was immunoprecipitated from cell lysates and ubiquitination was analyzed by Western blotting utilizing anti-ubiquitin antibodies. * Indicates aspecific band. Data shown are representative of three independent experiments.