Fig. 3

INHAT Function of NOC2L. In the compacted state of chromatin, histones form a spatial barrier for the RNA-polymerase to access to the DNA, which wind around these histones. When the lysine residue of histone is acetylated by HAT, the positive charge of lysine is neutralized, thus weakening the interactions between DNA and histones, allowing more space and making it more easily for RNA-polymerase to approach to the exposed DNA. When HDAC removes acetylation groups from histone, chromatin returns to the compacted state, forming a spatial barrier and making it difficult for RNA-polymerase to approach. When NOC2L occupies histone, it inhibits HAT activity to transfer acetylation group to the NOC2L-occupied histone. The acetylation level of histone is reduced, and the chromatin is in a condensed state where transcription is inactivated