PLoS Biology (Jul 2010)

Active RNA polymerases: mobile or immobile molecular machines?

  • Argyris Papantonis,
  • Joshua D Larkin,
  • Youichiro Wada,
  • Yoshihiro Ohta,
  • Sigeo Ihara,
  • Tatsuhiko Kodama,
  • Peter R Cook

DOI
https://doi.org/10.1371/journal.pbio.1000419
Journal volume & issue
Vol. 8, no. 7
p. e1000419

Abstract

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It is widely assumed that active RNA polymerases track along their templates to produce a transcript. We test this using chromosome conformation capture and human genes switched on rapidly and synchronously by tumour necrosis factor alpha (TNFalpha); one is 221 kbp SAMD4A, which a polymerase takes more than 1 h to transcribe. Ten minutes after stimulation, the SAMD4A promoter comes together with other TNFalpha-responsive promoters. Subsequently, these contacts are lost as new downstream ones appear; contacts are invariably between sequences being transcribed. Super-resolution microscopy confirms that nascent transcripts (detected by RNA fluorescence in situ hybridization) co-localize at relevant times. Results are consistent with an alternative view of transcription: polymerases fixed in factories reel in their respective templates, so different parts of the templates transiently lie together.