TAF9 RNA polymerase II, TATA box binding protein (TBP)-associated factor, 32kDa, also known as TAF9, is a protein that in humans is encoded by the TAF9gene.[1][2]
Initiation of transcription by RNA polymerase II requires the activities of more than 70 polypeptides. The protein complex 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 smaller subunits of TFIID that binds to the basal transcription factor GTF2B as well as to several transcriptional activators such as p53 and VP16. A similar but distinct gene (TAF9B) has been found on the X chromosome and a pseudogene has been identified on chromosome 19. Alternative splicing results in multiple transcript variants encoding different isoforms.[1]
Structure
The 17-amino-acid-long trans-activating domains (TAD) of several transcription factors were reported to bind directly to TAF9: p53, VP16, HSF1, NF-IL6, NFAT1, NF-κB, and ALL1/MLL1.[3] Inside of these 17 amino acids, a unique Nine-amino-acid transactivation domain (9aaTAD) was identified for each reported transcription factor.[4] 9aaTAD is a novel domain common to a large superfamily of eukaryotic transcription factors represented by Gal4, Oaf1, Leu3, Rtg3, Pho4, Gln4, Gcn4 in yeast and by p53, NFAT, NF-κB and VP16 in mammals.[5] TAF9 is supposed to be a universal transactivation cofactor for 9aaTAD transcription factors.[4]
↑Evans SC, Foster CJ, El-Naggar AK, Lozano G (April 1999). "Mapping and mutational analysis of the human TAF2G gene encoding a p53 cofactor". Genomics. 57 (1): 182–3. doi:10.1006/geno.1999.5745. PMID10191103.
↑Uesugi M, Nyanguile O, Lu H, Levine AJ, Verdine GL (August 1997). "Induced alpha helix in the VP16 activation domain upon binding to a human TAF". Science. 277 (5330): 1310–3. doi:10.1126/science.277.5330.1310. PMID9271577.Uesugi M, Verdine GL (December 1999). "The alpha-helical FXXPhiPhi motif in p53: TAF interaction and discrimination by MDM2". Proc. Natl. Acad. Sci. U.S.A. 96 (26): 14801–6. doi:10.1073/pnas.96.26.14801. PMC24728. PMID10611293.Choi Y, Asada S, Uesugi M (May 2000). "Divergent hTAFII31-binding motifs hidden in activation domains". J. Biol. Chem. 275 (21): 15912–6. doi:10.1074/jbc.275.21.15912. PMID10821850.Venot C, Maratrat M, Sierra V, Conseiller E, Debussche L (April 1999). "Definition of a p53 transactivation function-deficient mutant and characterization of two independent p53 transactivation subdomains". Oncogene. 18 (14): 2405–10. doi:10.1038/sj.onc.1202539. PMID10327062.Lin J, Chen J, Elenbaas B, Levine AJ (May 1994). "Several hydrophobic amino acids in the p53 amino-terminal domain are required for transcriptional activation, binding to mdm-2 and the adenovirus 5 E1B 55-kD protein". Genes Dev. 8 (10): 1235–46. doi:10.1101/gad.8.10.1235. PMID7926727.
↑ 4.04.1Piskacek S, Gregor M, Nemethova M, Grabner M, Kovarik P, Piskacek M (June 2007). "Nine-amino-acid transactivation domain: establishment and prediction utilities". Genomics. 89 (6): 756–68. doi:10.1016/j.ygeno.2007.02.003. PMID17467953.
↑The prediction for 9aa TADs (for both acidic and hydrophilic transactivation domains) is available online from National EMBnet-Node Austria ("9aaTAD Prediction Webtool". EMBnet AUSTRIA. Archived from the original on 2007-07-01. Retrieved 2009-01-10.)
↑Tao Y, Guermah M, Martinez E, Oelgeschläger T, Hasegawa S, Takada R, Yamamoto T, Horikoshi M, Roeder RG (Mar 1997). "Specific interactions and potential functions of human TAFII100". J. Biol. Chem. 272 (10): 6714–21. doi:10.1074/jbc.272.10.6714. PMID9045704.
Parada CA, Yoon JB, Roeder RG (1995). "A novel LBP-1-mediated restriction of HIV-1 transcription at the level of elongation in vitro". J. Biol. Chem. 270 (5): 2274–83. doi:10.1074/jbc.270.5.2274. PMID7836461.
Wang Z, Morris GF, Rice AP, Xiong W, Morris CB (1996). "Wild-type and transactivation-defective mutants of human immunodeficiency virus type 1 Tat protein bind human TATA-binding protein in vitro". J. Acquir. Immune Defic. Syndr. Hum. Retrovirol. 12 (2): 128–38. doi:10.1097/00042560-199606010-00005. PMID8680883.
Zhou Q, Sharp PA (1996). "Tat-SF1: cofactor for stimulation of transcriptional elongation by HIV-1 Tat". Science. 274 (5287): 605–10. doi:10.1126/science.274.5287.605. PMID8849451.
Tao Y, Guermah M, Martinez E, Oelgeschläger T, Hasegawa S, Takada R, Yamamoto T, Horikoshi M, Roeder RG (1997). "Specific interactions and potential functions of human TAFII100". J. Biol. Chem. 272 (10): 6714–21. doi:10.1074/jbc.272.10.6714. PMID9045704.
García-Martínez LF, Ivanov D, Gaynor RB (1997). "Association of Tat with purified HIV-1 and HIV-2 transcription preinitiation complexes". J. Biol. Chem. 272 (11): 6951–8. doi:10.1074/jbc.272.11.6951. PMID9054383.
Ogryzko VV, Kotani T, Zhang X, Schiltz RL, Howard T, Yang XJ, Howard BH, Qin J, Nakatani Y (1998). "Histone-like TAFs within the PCAF histone acetylase complex". Cell. 94 (1): 35–44. doi:10.1016/S0092-8674(00)81219-2. PMID9674425.
Vassilev A, Yamauchi J, Kotani T, Prives C, Avantaggiati ML, Qin J, Nakatani Y (1999). "The 400 kDa subunit of the PCAF histone acetylase complex belongs to the ATM superfamily". Mol. Cell. 2 (6): 869–75. doi:10.1016/S1097-2765(00)80301-9. PMID9885574.
Evans SC, Foster CJ, El-Naggar AK, Lozano G (1999). "Mapping and mutational analysis of the human TAF2G gene encoding a p53 cofactor". Genomics. 57 (1): 182–3. doi:10.1006/geno.1999.5745. PMID10191103.
