TAF7 explained

Transcription initiation factor TFIID subunit 7 also known as TAFII55 is a protein that in humans is encoded by the TAF7 gene.^[1]

Function

The intronless gene for this transcription coactivator is located between the protocadherin beta and gamma gene clusters on chromosome 5. The protein encoded by this gene is a component of the TFIID protein complex, a complex which binds to the TATA box in class II promoters and recruits RNA polymerase II and other factors. This particular subunit interacts with the largest TFIID subunit, as well as multiple transcription activators. The protein is required for transcription by promoters targeted by RNA polymerase II.^[2]

The general transcription factor, TFIID, consists of the TATA-binding protein (TBP) associated with a series of TBP-associated factors (TAFs) that together participate in the assembly of the transcription preinitiation complex. TAFII55 binds to TAFII250 and inhibits its acetyltransferase activity. The exact role of TAFII55 is currently unknown but studies have shown that it interacts with the C-jun pathway.^[3] The conserved region is situated towards the N-terminal of the protein.^[4] This entry talks about the N-terminal domain.

Crystallographic studies have revealed a very significant hydrophobic pocket between TAF7 and TAF1, its main binding partner. Due to the incredible hydrophobicity of this interaction, it is unlikely that TAF1 would be able to fold properly without the presence of TAF7. Thus, it is possible that TAF7 is required for proper production of TAF1^[5]

Interactions

TAF7 has been shown to interact with:

• TAF15,^[6]
• TAF1,^[4] and
• TATA binding protein.^{[7] [8]}

Further reading

• Zhou Q, Sharp PA . Novel mechanism and factor for regulation by HIV-1 Tat . The EMBO Journal . 14 . 2 . 321–8 . January 1995 . 7835343 . 398086 . 10.1002/j.1460-2075.1995.tb07006.x.
• Parada CA, Yoon JB, Roeder RG . A novel LBP-1-mediated restriction of HIV-1 transcription at the level of elongation in vitro . The Journal of Biological Chemistry . 270 . 5 . 2274–83 . February 1995 . 7836461 . 10.1074/jbc.270.5.2274 . free .
• Richard Gaynor . Ou SH, Garcia-Martínez LF, Paulssen EJ, Gaynor RB . Role of flanking E box motifs in human immunodeficiency virus type 1 TATA element function . Journal of Virology . 68 . 11 . 7188–99 . November 1994 . 7933101 . 237158 . 10.1128/JVI.68.11.7188-7199.1994.
• Cross SH, Charlton JA, Nan X, Bird AP . Purification of CpG islands using a methylated DNA binding column . Nature Genetics . 6 . 3 . 236–44 . March 1994 . 8012384 . 10.1038/ng0394-236 . 12847618 .
• Kashanchi F, Piras G, Radonovich MF, Duvall JF, Fattaey A, Chiang CM, Roeder RG, Brady JN . Direct interaction of human TFIID with the HIV-1 transactivator tat . Nature . 367 . 6460 . 295–9 . January 1994 . 8121496 . 10.1038/367295a0 . 1994Natur.367..295K . 4362048 .
• Wang Z, Morris GF, Rice AP, Xiong W, Morris CB . Wild-type and transactivation-defective mutants of human immunodeficiency virus type 1 Tat protein bind human TATA-binding protein in vitro . Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology . 12 . 2 . 128–38 . June 1996 . 8680883 . 10.1097/00042560-199606010-00005 . free .
• Lavigne AC, Mengus G, May M, Dubrovskaya V, Tora L, Chambon P, Davidson I . Multiple interactions between hTAFII55 and other TFIID subunits. Requirements for the formation of stable ternary complexes between hTAFII55 and the TATA-binding protein . The Journal of Biological Chemistry . 271 . 33 . 19774–80 . August 1996 . 8702684 . 10.1074/jbc.271.33.19774 . free .
• Pendergrast PS, Morrison D, Tansey WP, Hernandez N . Mutations in the carboxy-terminal domain of TBP affect the synthesis of human immunodeficiency virus type 1 full-length and short transcripts similarly . Journal of Virology . 70 . 8 . 5025–34 . August 1996 . 8764009 . 190456 . 10.1128/JVI.70.8.5025-5034.1996.
• Kashanchi F, Khleif SN, Duvall JF, Sadaie MR, Radonovich MF, Cho M, Martin MA, Chen SY, Weinmann R, Brady JN . Interaction of human immunodeficiency virus type 1 Tat with a unique site of TFIID inhibits negative cofactor Dr1 and stabilizes the TFIID-TFIIA complex . Journal of Virology . 70 . 8 . 5503–10 . August 1996 . 8764062 . 190508 . 10.1128/JVI.70.8.5503-5510.1996.
• Rowlands JC, McEwan IJ, Gustafsson JA . Trans-activation by the human aryl hydrocarbon receptor and aryl hydrocarbon receptor nuclear translocator proteins: direct interactions with basal transcription factors . Molecular Pharmacology . 50 . 3 . 538–48 . September 1996 . 8794892 .
• Zhou Q, Sharp PA . Tat-SF1: cofactor for stimulation of transcriptional elongation by HIV-1 Tat . Science . 274 . 5287 . 605–10 . October 1996 . 8849451 . 10.1126/science.274.5287.605 . 1996Sci...274..605Z . 13266489 .
• García-Martínez LF, Ivanov D, Gaynor RB . Association of Tat with purified HIV-1 and HIV-2 transcription preinitiation complexes . The Journal of Biological Chemistry . 272 . 11 . 6951–8 . March 1997 . 9054383 . 10.1074/jbc.272.11.6951 . free .
• Dantonel JC, Murthy KG, Manley JL, Tora L . Transcription factor TFIID recruits factor CPSF for formation of 3' end of mRNA . Nature . 389 . 6649 . 399–402 . September 1997 . 9311784 . 10.1038/38763 . 1997Natur.389..399D . 4413324 .
• Bertolotti A, Melot T, Acker J, Vigneron M, Delattre O, Tora L . EWS, but not EWS-FLI-1, is associated with both TFIID and RNA polymerase II: interactions between two members of the TET family, EWS and hTAFII68, and subunits of TFIID and RNA polymerase II complexes . Molecular and Cellular Biology . 18 . 3 . 1489–97 . March 1998 . 9488465 . 108863 . 10.1128/mcb.18.3.1489.
• Fraser RA, Heard DJ, Adam S, Lavigne AC, Le Douarin B, Tora L, Losson R, Rochette-Egly C, Chambon P . The putative cofactor TIF1alpha is a protein kinase that is hyperphosphorylated upon interaction with liganded nuclear receptors . The Journal of Biological Chemistry . 273 . 26 . 16199–204 . June 1998 . 9632676 . 10.1074/jbc.273.26.16199 . free .
• Furukawa T, Tanese N . Assembly of partial TFIID complexes in mammalian cells reveals distinct activities associated with individual TATA box-binding protein-associated factors . The Journal of Biological Chemistry . 275 . 38 . 29847–56 . September 2000 . 10896937 . 10.1074/jbc.M002989200 . free .
• Yuan CX, Gurley WB . Potential targets for HSF1 within the preinitiation complex . Cell Stress & Chaperones . 5 . 3 . 229–42 . July 2000 . 11005381 . 312889 .
• Wu Q, Zhang T, Cheng JF, Kim Y, Grimwood J, Schmutz J, Dickson M, Noonan JP, Zhang MQ, Myers RM, Maniatis T . Comparative DNA sequence analysis of mouse and human protocadherin gene clusters . Genome Research . 11 . 3 . 389–404 . March 2001 . 11230163 . 311048 . 10.1101/gr.167301 .
• Zhou T, Chiang CM . The intronless and TATA-less human TAF(II)55 gene contains a functional initiator and a downstream promoter element . The Journal of Biological Chemistry . 276 . 27 . 25503–11 . July 2001 . 11340078 . 10.1074/jbc.M102875200 . free .

Notes and References

1. Chiang CM, Roeder RG . Cloning of an intrinsic human TFIID subunit that interacts with multiple transcriptional activators . Science . 267 . 5197 . 531–6 . January 1995 . 7824954 . 10.1126/science.7824954 . 1995Sci...267..531C . 21236901 .
2. Web site: Entrez Gene: TAF7 TAF7 RNA polymerase II, TATA box binding protein (TBP)-associated factor, 55kDa.
3. Munz C, Psichari E, Mandilis D, Lavigne AC, Spiliotaki M, Oehler T, Davidson I, Tora L, Angel P, Pintzas A . TAF7 (TAFII55) plays a role in the transcription activation by c-Jun . The Journal of Biological Chemistry . 278 . 24 . 21510–6 . June 2003 . 12676957 . 10.1074/jbc.M212764200 . free .
4. Gegonne A, Weissman JD, Singer DS . TAFII55 binding to TAFII250 inhibits its acetyltransferase activity . Proceedings of the National Academy of Sciences of the United States of America . 98 . 22 . 12432–7 . October 2001 . 11592977 . 60071 . 10.1073/pnas.211444798 . 2001PNAS...9812432G . free .
5. Bhattacharya S, Lou X, Hwang P, Rajashankar KR, Wang X, Gustafsson JÅ, Fletterick RJ, Jacobson RH, Webb P . Jan-Åke Gustafsson . Structural and functional insight into TAF1-TAF7, a subcomplex of transcription factor II D . Proceedings of the National Academy of Sciences of the United States of America . 111 . 25 . 9103–8 . June 2014 . 24927529 . 10.1073/pnas.1408293111 . 4078864. 2014PNAS..111.9103B . free .
6. Bertolotti A, Melot T, Acker J, Vigneron M, Delattre O, Tora L . EWS, but not EWS-FLI-1, is associated with both TFIID and RNA polymerase II: interactions between two members of the TET family, EWS and hTAFII68, and subunits of TFIID and RNA polymerase II complexes . Molecular and Cellular Biology . 18 . 3 . 1489–97 . March 1998 . 9488465 . 108863 . 10.1128/mcb.18.3.1489.
7. Pointud JC, Mengus G, Brancorsini S, Monaco L, Parvinen M, Sassone-Corsi P, Davidson I . The intracellular localisation of TAF7L, a paralogue of transcription factor TFIID subunit TAF7, is developmentally regulated during male germ-cell differentiation . Journal of Cell Science . 116 . Pt 9 . 1847–58 . May 2003 . 12665565 . 10.1242/jcs.00391 . 24519687 .
8. Bellorini M, Lee DK, Dantonel JC, Zemzoumi K, Roeder RG, Tora L, Mantovani R . CCAAT binding NF-Y-TBP interactions: NF-YB and NF-YC require short domains adjacent to their histone fold motifs for association with TBP basic residues . Nucleic Acids Research . 25 . 11 . 2174–81 . June 1997 . 9153318 . 146709 . 10.1093/nar/25.11.2174 .