Fig. 6.

HDAC7 interacts and deacetylates STAT3. a-c, HDAC7 regulates STAT3 acetylation. Western blot analysis of acetylation and phosphorylation of STAT3 in the individual lung tumors from Hdac7 ^+/−/K-Ras and control mice (a), H1299 human cancer cells expressing shHDAC7 (b) and an exogenous mouse Hdac7 cDNA (c) with antibodies specific for Stat3, or acetyl-STAT3(K685) or phospho-Stat3(p-Y705). d-g In vivo interaction of Hdac7 and Stat3 proteins. Immunoprecipitation -Western blots analyses of the endougenous HDAC7 and STAT3 in H1299 human cancer cells (d) and lung tumors from control K-Ras mice (e), and the exogenous mouse Hdac7 and Stat3 proteins expressed in 293 T cells (f and g) with the antibodies as indicated. h GST pull down-Western blot assay of affinity-purified GST-Hdac7 fusion protein and Flag-tagged Stat3 protein. Anti-Hdac7 and -Stat3 were used for blot to detect GST-Hdac7 fusion proteins and Stat3 protein, respectively. i In vitro deacetylase assay with affinity purified GST-HDAC7(aa 445–938), GST-HDAC7(aa 445–938)-AWA and Flag-tagged Stat3 proteins. Acetyl-STAT3 was detected with pan anti-acetyl-Lysine antibodies. Images are representatives of three experiments