Methylation of Lys4 by Set7/9 is associated with transcription activation. Methylation by Set7/9 inhibits methylation of Lys9 by SUV39H1 and vice versa (Wang et al 2001b
). Methylation of Lys4 enhances acetylation of H4 by p300. Methylation of Lys4 prevents the association of the NuRD?
complex with the H3 tail. NuRD?
contains two histone deacetylaces, HDAC1 and HDAC2, and is associated with transcription repression.