transcription

Transcription is performed by three different RNA polymerases in eukaryotic cells:
 RNA polymerase I transcribes ribosomal DNA into ribosomal RNA used in the biogenesis of ribosomes;
 RNA polymerase II transcribes genes into mRNA;
 RNA polymerase III synthesizes transfer RNA and small nuclear RNA.

Although RNA polymerase I and III transcribe DNA at a high rate, the genomic length of DNA transcribed is rather small compared with the length of all mRNA genes transcribed by RNA polymerase II. RNA polymerase II would be expected to ’scan’ a much larger portion of the genome than RNA polymerase I and III, and could therefore be considered to be a ’better’ sensor than the two other RNA polymerases.

Transcription and DNA lesions

When RNA polymerase II complexes are blocked at sites of DNA lesions, they are able to recruit DNA-repair proteins to perform transcription-coupled repair (TCR), a specialized nucleotide-excision repair (NER) pathway that removes transcription-blocking lesions and that does not seem to be associated with RNA polymerase I or III. RNA polymerase II is perfectly suited to act as a sensor of DNA perturbations in the template and to alert the cell by activating DNA-damage signalling pathways.

Pathology

 chromatin remodeling disorders
 trichothiodystrophy
 Pathology of Swi/Snf family of nucleosome-remodeling complexes

• rhabdoid tumor syndrome (INI1/SNF5)

 transcriptional derepression

See also

 transcription factors
 transcription machinery
 transcription networks
 transcriptional derepression

Videos

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References

 From DNA sequence to transcriptional behaviour: a quantitative approach. Segal E, Widom J. Nat Rev Genet. 2009 Jul;10(7):443-56. Review.PMID: 19506578

 Transcription factories: gene expression in unions? Sutherland H, Bickmore WA. Nat Rev Genet. 2009 Jul;10(7):457-66. PMID: 19506577

 Saunders A, Core LJ, Lis JT. Breaking barriers to transcription elongation. Nat Rev Mol Cell Biol. 2006 Aug;7(8):557-67. PMID: 16936696

 Mellor J. Dynamic nucleosomes and gene transcription. Trends Genet. 2006 Jun;22(6):320-9. PMID: 16631276

 Arias AM, Hayward P. Filtering transcriptional noise during development: concepts and mechanisms. Nat Rev Genet. 2006 Jan;7(1):34-44. PMID: 16369570

 Darzacq X, Singer RH, Shav-Tal Y. Dynamics of transcription and mRNA export. Curr Opin Cell Biol. 2005 Jun;17(3):332-9. PMID: 15901505

 Chakalova L, Debrand E, Mitchell JA, Osborne CS, Fraser P. Replication and transcription: shaping the landscape of the genome. Nat Rev Genet. 2005 Sep;6(9):669-77. PMID: 16094312

 Arias AM, Hayward P. Filtering transcriptional noise during development: concepts and mechanisms. Nat Rev Genet. 2006 Jan;7(1):34-44. PMID: 16369570

 Gibson G, Weir B. The quantitative genetics of transcription. Trends Genet. 2005 Nov;21(11):616-23. PMID: 16154229

 West AG, Fraser P. Remote control of gene transcription. Hum Mol Genet. 2005 Apr 15;14 Spec No 1:R101-11. PMID: 15809261

 Semon M, Duret L. Evidence that functional transcription units cover at least half of the human genome. Trends Genet. 2004 May;20(5):229-32. PMID: 15109775

 Zurita M, Merino C. The transcriptional complexity of the TFIIH complex. Trends Genet. 2003 Oct;19(10):578-84. PMID: 14550632

 Williams RR. Transcription and the territory: the ins and outs of gene positioning. Trends Genet. 2003 Jun;19(6):298-302. PMID: 12801719

 Citterio E, Vermeulen W, Hoeijmakers JH. Transcriptional healing. Cell. 2000 May 26;101(5):447-50. PMID: 10850486