Figure 3

HDAC1 modulates SPRR2A induced changes in p53 and p300 acetylation. (A) Exposure to the deacetylase inhibitor trichostatin A (TSA) causes acetylation of most all of the p53 in SPRR2A cells, indicating a role for Class I and II deacetylases in the cellular affects of SPRR2A expression. Concomitant with this TSA increase in p53 acetylation is an increase in p21 expression. (B) HDAC1 mRNA and protein expression are increased in SPRR2A cells. (C) HDAC1 co-immunoprecipitates with p300 and there is more HDAC1/p300 binding in SPRR2A cells. (D) Knockdown of HDAC1 with siRNA: increases p21 protein and mRNA expression; restores acetylated p53 in SPRR2A cells to levels seen in the untreated vector control cells; and increases acetylated p300. Successful HDAC1 knock down was verified by both real-time PCR and western blotting. Real time PCR analysis: comparative 2-ΔΔ CT method (GAPDH internal control).