<p>A schematic representation of pCTAP-Fli1. Streptavidin and calmodulin resins bind to streptavidin-binding peptide (SBP) and calmodulin-binding peptide (CBP), respectively. ATA: A-terminal activation domain, EBD: Ets binding domain, CTA: C-terminal activation domain. <b>B.</b> Foreskin fibroblasts were grown to subconfluence and serum-starved for 48 hours. Equal amount of protein from whole cell lysates was subjected to immunoprecipitation with or without anti-Fli1 antibody. The levels of Fli1, HDAC1, and HDAC3 proteins in precipitates were determined by immunoblotting. The levels of Fli1, HDAC1 and HDAC3 in whole cell lysates were determined by Western blotting. <b>C.</b> 293 T cells were transfected with pCTAP expression vector encoding wild type Fli1 along with PCAF, PCAFΔHAT, or HDAC1 expression vectors, and incubated for 48 hours. Total cell extracts were subjected to immunoprecipitation using streptavidin-coupled agarose beads (SA beads), followed by immunoblotting using rabbit anti-acetylated lysine antibody (AcK). To visualize the total levels of ectopically expressed Fli1, the same membrane was stripped and reprobed with anti-calmodulin binding peptide antibody. The levels of Flag-tagged proteins in cell lysates were determined by Western blotting. <b>D.</b> 293 T cells were transfected with pCTAP wild type Fli1 along with PCAF or PCAFΔHAT expression vectors. Six hours after the transfection, HDAC1 antisense oligonucleotide (HDAC1 AS oligo) or HDAC1 sense oligonucleotide (HDAC1 S oligo) were added to the cells. Whole cells lysates were prepared 48 hours after transfection. The levels of acetylated Fli1 and Flag-tagged proteins were determined as described above. The efficacy of HDAC1 AS oligo was evaluated by Western blotting.</p