Histone acetylation and gene induction in human cells.

An antibody recognising acetylated core histones was used to immunoprecipitate chromatin fragments from proliferating human K562 cells and from cells induced to differentiate with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). The DNA of the acetylated chromatin was probed with sequences of platelet derived growth factor B chain (PDGF-B), a gene which is induced to strong expression upon differentiation. A high level of acetylation was observed before gene induction and no change seen following induction. This implies that core histone acetylation is an essential precondition for transcription.