The expression of HATs SRC-1, p300, TIP60, and ATF2 in normal CD4⁺ and CD8⁺ lymphocytes. Nuclear or whole-cell proteins were extracted from purified CD4⁺ and CD8⁺ T cells. The expression of (A) SRC-1, (B) p300, (C) TIP60, and (D) ATF2 was evaluated by Western blot. C23 was used as a loading control for nuclear proteins. Nuclear extracts from Jurkat T cells and HeLa cells were used as positive controls for the anti-p300 antibody. Vertical lines have been inserted to indicate where a gel lane was cut. These gels came from 2 different experiments. (E) The ratio of AFT2 to C23 was calculated as a ratio of density for AFT2 and C23 bands measured with National Institutes of Health (Bethesda, MD) Image 1.63 software.