Fast transcription rates of RNA polymerase II in human cells

Paolo Maiuri, Anna Knezevich, Alex De Marco, Davide Mazza, Anna Kula, Jim G. McNally, Alessandro Marcello

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66 Citations (Scopus)


Averaged estimates of RNA polymerase II (RNAPII) elongation rates in mammalian cells have been shown to range between 1.3 and 4.3 kb min -1. In this work, nascent RNAs from an integrated human immunodeficiency virus type 1-derived vector were detectable at the single living cell level by fluorescent RNA tagging. At steady state, a constant number of RNAs was measured corresponding to a minimal density of polymerases with negligible fluctuations over time. Recovery of fluorescence after photobleaching was complete within seconds, indicating a high rate of RNA biogenesis. The calculated transcription rate above 50 kb min -1 points towards a wide dynamic range of RNAPII velocities in living cells.

Original languageEnglish
Pages (from-to)1280-1285
Number of pages6
JournalEMBO Reports
Issue number12
Publication statusPublished - Dec 2011
Externally publishedYes


  • FRAP
  • HIV
  • live imaging
  • RNA polymerase II
  • transcription

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