TAF1
TAF1 (TATA-box binding protein associated factor 1, also known as TAFII250, KAT4 and CCG1) is the largest subunit of the TFIID basal transcription factor complex. It acts as a scaffold for complex assembly and carries kinase and histone acetyltransferase activities. Browse Assay Genie's current range of TAF1 research reagents below, or read on for the biology behind the target.
TAF1 is the largest component and core scaffold of TFIID, the basal transcription factor complex that plays a major role in initiating RNA polymerase II (Pol II)-dependent transcription. TFIID recognises and binds promoters, with or without a TATA box, through its TATA-box-binding protein (TBP) subunit, and promotes assembly of the pre-initiation complex. TAF1 nucleates assembly of the complex and forms a promoter DNA-binding subcomplex together with TAF7 and TAF2. The complex also contains TAF3 to TAF6, TAF8 to TAF13 and TBP. The TAF1 subunit binds core promoter sequences around the transcription start site, and it also binds activators and other transcriptional regulators, which affects the rate of transcription initiation.
The TAF1 protein is notable for its enzymatic activities. It has novel N- and C-terminal Ser/Thr kinase domains that can autophosphorylate or transphosphorylate other transcription factors. It phosphorylates TP53 on Thr-55, which leads to MDM2-mediated degradation of TP53, and phosphorylates GTF2A1 and GTF2F1 on serine residues. It also has DNA-binding activity and histone acetyltransferase activity towards histones H3 and H4. NCBI Gene further describes a ubiquitin-activating/conjugating function. TAF1 is essential for progression through the G1 phase of the cell cycle and is localised to the nucleus. It belongs to the TAF1 family.
The TAF1 gene has been listed under many names, including TAFII250, KAT4, CCG1, CCGS, BA2R and TAF2A, and earlier as TBP-associated factor, RNA polymerase II, A, 250kD. HGNC places it in the lysine acetyltransferase, bromodomain-containing and TFIID subunit gene groups. Mutations in the gene result in dystonia 3, torsion, X-linked, a dystonia-parkinsonism disorder. The gene is part of a complex transcription unit, TAF1/DYT3, and alternative splicing yields multiple transcript variants, some of which share exons with downstream DYT3 sequences. A mouse ortholog, Taf1, is recorded.
TAF1 nucleates TFIID assembly and promoter binding, making it central to studies of pre-initiation complex formation and RNA polymerase II transcription.
As a lysine acetyltransferase with a bromodomain, TAF1 acetylates histones H3 and H4, linking general transcription factors to chromatin modification.
TAF1 is essential for G1 progression and phosphorylates TP53 on Thr-55, leading to MDM2-mediated TP53 degradation.
Mutations in the TAF1 gene result in X-linked dystonia 3, a dystonia-parkinsonism disorder, and the TAF1/DYT3 transcription unit is studied in this context.
TAF1 is the largest subunit and core scaffold of TFIID, which initiates RNA polymerase II transcription. It nucleates complex assembly, binds core promoter DNA with TAF7 and TAF2, and has kinase and histone acetyltransferase activities. It is also essential for G1 progression of the cell cycle.
TAF1 is also called TAFII250, KAT4, CCG1, CCGS, BA2R, TAF2A, NSCL2 and DYT3, and its UniProt name is transcription initiation factor TFIID subunit 1. Alternative splicing produces multiple transcript variants, some of which share exons with the downstream DYT3 portion of the TAF1/DYT3 transcription unit.
Mutations in the TAF1 gene result in dystonia 3, torsion, X-linked, a dystonia-parkinsonism disorder. A mouse ortholog, Taf1, exists, and TAFs are described as evolutionarily conserved; check the datasheet of any product for its validated reactivity.
Other TBP-associated factors and related transcription initiation proteins with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P21675; product specifications from Assay Genie datasheets.