Acetylation of Histones in Chromatin and Its Functions in Gene Transcription

Histones are structural proteins organizing DNA into nucleosomes in chromatin environment.Lysine residues of histone N-terminal have positive charge, facilitating stable interaction with negatively charged DNA in nucleosomes.Each lysine residue can be covalently modified by the addition of acetyl group and removal of it, which is called as histone acetylation and deacetylation.These modifications are catalyzed by histone acetyltransferases and deacetylases, respectively.Histone acetylation weakens interaction between histone and DNA in nucleosomes, increasing the accessibility of nucleosomal DNA to other proteins such as transcription factors and coactivators.In addition, acetylated lysine residues act as recognition points for bromodomain that is present in many kinds of coactivators.Thus, histone acetylation plays essential roles in activating chromatin structure and promoting nuclear events such as gene transcription, DNA replication and DNA repair.The failure of histone acetylation and deacetylation causes serious diseases including cancer.This review explains the basic concept of histone acetylation based on studies in biochemistry and molecular biology fields and may be helpful to understand chromatin structure, histone modifications and epigenetics.