SAP18Histone deacetylase complex subunit SAP18 is an enzyme that in humans is encoded by the SAP18 gene.FunctionHistone acetylation plays a key role in the regulation of eukaryotic gene expression. Multisubunit complexes catalyze histone acetylation and deacetylation. The protein encoded by this gene is a histone deacetylase complex component, including SIN3, SAP30, HDAC1, HDAC2, RbAp46, RbAp48, and other polypeptides. This protein directly interacts with SIN3 and enhances SIN3-mediated transcriptional repression when tethered to the promoter. Additionally, SAP18s splice variants are implicated in apoptotic cycles.InteractionsSAP18 has been shown to interact with POLE2, and RGS10.