Figure 5. UVB-induced differential expression of posttranslationally modified acetyl-H3 and H2B was associated with decreased total HAT activity. (A) UVB-exposed and unexposed LECs were harvested and processed for nuclear protein extraction. Extract was resolved through 4–20% SDS-PAGE and immunoblotted with anti-acetyl histone or anti-histone antibodies as shown. (B) Total HAT activity was measured after multiple UVB exposures following the company’s protocol (Epigentek), and data were compared with results from untreated samples. The data represent mean ± SEM of three independent experiments. Asterisks indicate statistically significant difference (p < 0.001 vs. corresponding control).