Active RNA polymerases: mobile or immobile molecular machines?

PLoS Biol. 2010 Jul 13;8(7):e1000419. doi: 10.1371/journal.pbio.1000419.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Pairing / genetics
  • Cells, Cultured
  • Chromosomes, Human, Pair 14 / genetics
  • DNA-Directed RNA Polymerases / metabolism*
  • Enzyme Activation / drug effects
  • Humans
  • In Situ Hybridization, Fluorescence
  • Introns / genetics
  • Protein Binding / drug effects
  • RNA Transport / drug effects
  • Repressor Proteins / metabolism
  • Time Factors
  • Transcription, Genetic / drug effects
  • Transcriptional Activation / drug effects
  • Transcriptional Activation / genetics
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Repressor Proteins
  • SAMD4A protein, human
  • Tumor Necrosis Factor-alpha
  • DNA-Directed RNA Polymerases