Alternative titles; symbols
HGNC Approved Gene Symbol: TAF12
Cytogenetic location: 1p35.3 Genomic coordinates (GRCh38): 1:28,602,850-28,648,269 (from NCBI)
Control of transcription by RNA polymerase II (see 180660) involves the basal transcription machinery, a collection of proteins which include TFIIB (TF2B; 189963), TFIIE (see 189962), TFIIF (see 189968), TBP (600075), TFIIA and TAFII250 (TAF2A; 313650). These, with RNA polymerase II, assemble into complexes which are modulated by transactivator proteins that bind to cis-regulatory elements located adjacent to the transcription start site. Some modulators interact directly with the basal complex, whereas others may act as bridging proteins linking transactivators to the basal transcription factors. Some of these associated factors are weakly attached while others are tightly associated with TBP in the TFIID complex. Among the latter are the TAF proteins. TAF components of the TFIID complex have been characterized from Drosophila cells and HeLa cells and many of the associated cDNAs have been cloned. Different TAFs are predicted to mediate the function of distinct transcriptional activators for a variety of gene promoters and RNA polymerases.
Mengus et al. (1995) used 2 oligomer probes designed from purified TAF2J peptide sequences (also referred to as TAFII20) to screen a HeLa cDNA library. The deduced cDNA sequence of TAFII20 was 161 amino acids long and encoded a 20.7 kD protein, in agreement with the tryptic peptide sequences. The human sequence is 53% identical to Drosophila TAFII30alpha. The authors demonstrated that TAFII20 interacts directly with TBP as well as with TAFII28 (TAF2I; 600772) and TAFII30 (TAF2H; 600475).
Cryoelectron Microscopy
Bieniossek et al. (2013) presented the structure of the human core-TFIID complex, consisting of 2 copies each of TAF4 (601796), TAF5 (601787), TAF6 (602955), TAF9 (600822), and TAF12, determined by cryoelectron microscopy at 11.6-angstrom resolution. The structure revealed a 2-fold symmetric, interlaced architecture, with pronounced protrusions, that accommodates all conserved structural features of the TAFs including the histone folds. Bieniossek et al. (2013) further demonstrated that binding of 1 TAF8 (609514)-TAF10 (600475) complex breaks the original symmetry of the core-TFIID. Bieniossek et al. (2013) proposed that the resulting asymmetric structure serves as a functional scaffold to nucleate holo-TFIID assembly, by accreting 1 copy each of the remaining TAFs and TBP.
The International Radiation Hybrid Mapping Consortium mapped the TAF12 (TAF2J) gene to chromosome 1 (SGC30964).
Bieniossek, C., Papai, G., Schaffitzel, C., Garzoni, F., Chaillet, M., Scheer, E., Papadopoulos, P., Tora, L., Schultz, P., Berger, I. The architecture of human general transcription factor TFIID core complex. Nature 493: 699-702, 2013. [PubMed: 23292512] [Full Text: https://doi.org/10.1038/nature11791]
Mengus, G., May, M., Jacq, X., Staub, A., Tora, L., Chambon, P., Davidson, I. Cloning and characterization of hTAFII18, hTAFII20 and hTAFII28: three subunits of the human transcription factor TFIID. EMBO J. 14: 1520-1531, 1995. [PubMed: 7729427] [Full Text: https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0261-4189&date=1995&volume=14&issue=7&spage=1520]