BRF1 (gene) explained

Transcription factor IIIB 90 kDa subunit is a protein that in humans is encoded by the BRF1 gene.^{[1] [2] [3]}

Function

This gene encodes one of the three subunits of the RNA polymerase III transcription factor complex. This complex plays a central role in transcription initiation by RNA polymerase III on genes encoding tRNA, 5S rRNA, and other small structural RNAs. The gene product belongs to the TF2B family. Three alternatively spliced variants encoding three different isoforms, that function at different promoters transcribed by RNA polymerase III, have been identified. A transcript encoding a fourth isoform has not yet been completely characterized.

Interactions

BRF1 (gene) has been shown to interact with:

• RB1,^[4]
• RBL1,
• RBL2,^[5] and
• TBP^[6]

Further reading

• Chesnokov I, Chu WM, Botchan MR, Schmid CW . p53 inhibits RNA polymerase III-directed transcription in a promoter-dependent manner . Mol. Cell. Biol. . 16 . 12 . 7084–8 . 1997 . 8943363 . 10.1128/MCB.16.12.7084. 231711 .
• Chu WM, Wang Z, Roeder RG, Schmid CW . RNA polymerase III transcription repressed by Rb through its interactions with TFIIIB and TFIIIC2 . J. Biol. Chem. . 272 . 23 . 14755–61 . 1997 . 9169441 . 10.1074/jbc.272.23.14755 . free .
• Wang Z, Roeder RG . Three human RNA polymerase III-specific subunits form a subcomplex with a selective function in specific transcription initiation . Genes Dev. . 11 . 10 . 1315–26 . 1997 . 9171375 . 10.1101/gad.11.10.1315 . free .
• Sutcliffe JE, Cairns CA, McLees A, Allison SJ, Tosh K, White RJ . RNA polymerase III transcription factor IIIB is a target for repression by pocket proteins p107 and p130 . Mol. Cell. Biol. . 19 . 6 . 4255–61 . June 1999 . 10330166 . 104385 . 10.1128/mcb.19.6.4255.
• Hsieh YJ, Wang Z, Kovelman R, Roeder RG . Cloning and characterization of two evolutionarily conserved subunits (TFIIIC102 and TFIIIC63) of human TFIIIC and their involvement in functional interactions with TFIIIB and RNA polymerase III . Mol. Cell. Biol. . 19 . 7 . 4944–52 . 1999 . 10373544 . 10.1128/MCB.19.7.4944. 84305 .
• Hsieh YJ, Kundu TK, Wang Z, Kovelman R, Roeder RG . The TFIIIC90 subunit of TFIIIC interacts with multiple components of the RNA polymerase III machinery and contains a histone-specific acetyltransferase activity . Mol. Cell. Biol. . 19 . 11 . 7697–704 . November 1999 . 10523658 . 84812 . 10.1128/mcb.19.11.7697.
• McCulloch V, Hardin P, Peng W, Ruppert JM, Lobo-Ruppert SM . Alternatively spliced hBRF variants function at different RNA polymerase III promoters . EMBO J. . 19 . 15 . 4134–43 . August 2000 . 10921893 . 306597 . 10.1093/emboj/19.15.4134 .
• Johnston IM, Allison SJ, Morton JP, Schramm L, Scott PH, White RJ . CK2 forms a stable complex with TFIIIB and activates RNA polymerase III transcription in human cells . Mol. Cell. Biol. . 22 . 11 . 3757–68 . June 2002 . 11997511 . 133823 . 10.1128/MCB.22.11.3757-3768.2002 .
• Cabart P, Murphy S . Assembly of human small nuclear RNA gene-specific transcription factor IIIB complex de novo on and off promoter . J. Biol. Chem. . 277 . 30 . 26831–8 . 2002 . 12016223 . 10.1074/jbc.M203119200 . free .
• Willis IM . A universal nomenclature for subunits of the RNA polymerase III transcription initiation factor TFIIIB . Genes Dev. . 16 . 11 . 1337–8 . 2002 . 12066800 . 10.1101/gad.998102 . free .
• Stoecklin G, Colombi M, Raineri I, Leuenberger S, Mallaun M, Schmidlin M, Gross B, Lu M, Kitamura T, Moroni C . Functional cloning of BRF1, a regulator of ARE-dependent mRNA turnover . EMBO J. . 21 . 17 . 4709–18 . September 2002 . 12198173 . 126184 . 10.1093/emboj/cdf444.
• Weser S, Riemann J, Seifart KH, Meissner W . Assembly and isolation of intermediate steps of transcription complexes formed on the human 5S rRNA gene . Nucleic Acids Res. . 31 . 9 . 2408–16 . 2003 . 12711686 . 10.1093/nar/gkg345 . 154231 .
• Schmidlin M, Lu M, Leuenberger SA, Stoecklin G, Mallaun M, Gross B, Gherzi R, Hess D, Hemmings BA, Moroni C . The ARE-dependent mRNA-destabilizing activity of BRF1 is regulated by protein kinase B . EMBO J. . 23 . 24 . 4760–9 . December 2004 . 15538381 . 535089 . 10.1038/sj.emboj.7600477 .

Notes and References

1. Wang Z, Roeder RG . Structure and function of a human transcription factor TFIIIB subunit that is evolutionarily conserved and contains both TFIIB- and high-mobility-group protein 2-related domains . Proc Natl Acad Sci U S A . 92 . 15 . 7026–30 . August 1995 . 7624363 . 41464 . 10.1073/pnas.92.15.7026 . 1995PNAS...92.7026W . free .
2. Mital R, Kobayashi R, Hernandez N . RNA polymerase III transcription from the human U6 and adenovirus type 2 VAI promoters has different requirements for human BRF, a subunit of human TFIIIB . Mol Cell Biol . 16 . 12 . 7031–42 . January 1997 . 8943358 . 231706 . 10.1128/MCB.16.12.7031.
3. Web site: Entrez Gene: BRF1 BRF1 homolog, subunit of RNA polymerase III transcription initiation factor IIIB (S. cerevisiae).
4. June 2002 . Johnston IM, Allison SJ, Morton JP, Schramm L, Scott PH, White RJ . CK2 forms a stable complex with TFIIIB and activates RNA polymerase III transcription in human cells . Mol. Cell. Biol. . 22 . 11 . 3757–68 . 11997511 . 133823 . 10.1128/mcb.22.11.3757-3768.2002.
5. June 1999 . Sutcliffe JE, Cairns CA, McLees A, Allison SJ, Tosh K, White RJ . RNA polymerase III transcription factor IIIB is a target for repression by pocket proteins p107 and p130 . Mol. Cell. Biol. . 19 . 6 . 4255–61 . 10330166 . 104385 . 10.1128/mcb.19.6.4255.
6. August 2000 . McCulloch V, Hardin P, Peng W, Ruppert JM, Lobo-Ruppert SM . Alternatively spliced hBRF variants function at different RNA polymerase III promoters . EMBO J. . 19 . 15 . 4134–43 . 10921893 . 306597 . 10.1093/emboj/19.15.4134.