Figure 2.

Activation-dependent recruitment and release of heterochromatin 1 proteins on the HIV1 long terminal repeat. After 2 h of PMA treatment of J-Lat A1 cells, chromatin immunoprecipitation experiments were performed with antibodies specific for HP1α, HP1β and HP1γ (A), or histone H3 tail modifications (B). Enrichment in HP1 LTR chromatin was measured by quantitative PCR using primers spanning the TS region (see Fig 3C). Values are averages from three independent experiments. ac, acetylated; dimet, dimethylated; H, histone; HP1, heterochromatin protein 1; K, lysine; LTR, long terminal repeat; PMA, phorbol-myristate acetate; pS, phospho-Serine; TS, transcription start.