H4K16ac

H4K16ac is an epigenetic modification to the DNA packaging protein Histone H4. It is a mark that indicates the acetylation at the 16th lysine residue of the histone H4 protein. H4K16ac is unusual in that it has both transcriptional activation AND repression activities. The loss of H4K20me3 along with a reduction of H4K16ac is a strong indicator of cancer.

Acetylation of histone H4 on lysine 16 (H4K16ac) is especially important for chromatin structure and function in a variety of eukaryotes and is catalyzed by specific histone lysine acetyltransferases (HATs). H4K16 is particularly interesting because this is the only acetylatable site of the H4 N-terminal tail, and can influence the formation of a compact higher-order chromatin structure. Hypoacetylation of H4K16 appears to cause delayed recruitment of DNA repair proteins to sites of DNA damage in a mouse model of the premature aging syndrome Hutchinson Gilford progeria. H4K16ac also has roles in transcriptional activation and the maintenance of euchromatin.