Initiation of transcription by RNA polymerase II requires the activities of more than 70 polypeptides. The protein that coordinates these activities is transcription factor IID (TFIID), which binds to the core promoter to position the polymerase properly, serves as the scaffold for assembly of the remainder of the transcription complex, and acts as a channel for regulatory signals. TFIID is composed of the TATA-binding protein (TBP) and a group of evolutionarily conserved proteins known as TBP-associated factors or TAFs. TAFs may participate in basal transcription, serve as coactivators, function in promoter recognition or modify general transcription factors (GTFs) to facilitate complex assembly and transcription initiation. This gene encodes one of the larger subunits of TFIID that has been shown to potentiate transcriptional activation by retinoic acid, thyroid hormone and vitamin D3 receptors. In addition, this subunit interacts with the transcription factor CREB, which has a glutamine-rich activation domain, and binds to other proteins containing glutamine-rich regions. Aberrant binding to this subunit by proteins with expanded polyglutamine regions has been suggested as one of the pathogenetic mechanisms underlying a group of neurodegenerative disorders referred to as polyglutamine diseases.
130kD; 135 kD; C1; RNA polymerase II; RNA polymerase II TBP-associated factor subunit C; TAF(II)130; TAF(II)135; TAF2C; TAF2C1; TAF4 RNA polymerase II, TATA box binding protein (TBP)-associated factor, 135kDa; TAF4A; TAF4A RNA polymerase II; TAF4A RNA polymerase II, TATA box binding protein (TBP)-associated factor, 135 kD; TAFII 130; TAFII 135; TAFII-130; TAFII-135; TAFII130; TAFII135; TATA box binding protein (TBP)-associated factor; TATA box binding protein (TBP)-associated factor, RNA polymerase II, C1, 130kD; TATA box binding protein associated factor 4; TBP associated factor 4; TBP-associated factor 4; Transcription initiation factor TFIID 130 kDa subunit; transcription initiation factor TFIID 135 kD subunit; Transcription initiation factor TFIID 135 kDa subunit; Transcription initiation factor TFIID subunit 4