This family consists of several eukaryotic Sin3 associated polypeptide p18 (SAP18) sequences. SAP18 is known to be a component of the Sin3-containing complex which is responsible for the repression of transcription via the modification of histone polypeptides [1]. SAP18 is also present in the ASAP complex which is thought to be involved in the regulation of splicing during the execution of programmed cell death [2].

1: Histone deacetylases and SAP18, a novel polypeptide, are components of a human Sin3 complex. Zhang Y, Iratni R, Erdjument-Bromage H, Tempst P, Reinberg D; Cell 1997;89:357-364. PMID:9150135

2: ASAP, a novel protein complex involved in RNA processing and apoptosis. Schwerk C, Prasad J, Degenhardt K, Erdjument-Bromage H, White E, Tempst P, Kidd VJ, Manley JL, Lahti JM, Reinberg D; Mol Cell Biol 2003;23:2981-2990. PMID:12665594