Sin3A-associated protein 18 (SAP18)

Sin3A-associated protein 18 (SAP18) is a core component of the SIN3-HDAC (histone deacetylase) complex, which is essential for transcriptional repression via chromatin remodeling[1][3][4][5][6]. SAP18 interacts directly with Sin3, HDAC1, HDAC2, SAP30, RbAp46, and RbAp48, acting as an adapter to recruit the deacetylase complex to specific gene promoters where it mediates the formation of a repressive chromatin environment, thus inhibiting gene transcription[1][5][6]. It is also found as an auxiliary component of the exon junction complex involved in splicing, and as part of the ASAP complex, SAP18 plays a regulatory role in alternative splicing and apoptosis, affecting isoform production of apoptosis-related genes such as Bcl-X[1][5]. SAP18 has a ubiquitin-like fold important for protein-protein interactions[6]. Beyond transcription, SAP18 impacts viral replication (notably HIV-1) and lipid metabolism through various regulatory partners[4]. Disease associations include several cancers, neurodegenerative, and psychiatric disorders[1][5]. There are currently no approved drugs directly targeting SAP18, and it is not considered a direct therapeutic target but rather a multifunctional gene regulatory factor.

Other names

2HOR0202SAP18PSin3-associated polypeptide 18GIG3818 kDa Sin3-associated polypeptideSin3A associated protein 18Cell growth-inhibiting gene 38 proteinSin3-associated polypeptide p18SAP18phistone deacetylase complex subunit SAP18cell growth inhibiting protein 38epididymis secretory sperm binding proteinSinbp1