Actin is part of pre-initiation complexes and is necessary for transcription by RNA polymerase II

Wilma A. Hofmann, Ljuba Stojiljkovic, Beata Fuchsova, Gabriela M. Vargas, Evangelos Mavrommatis, Vlada Philimonenko, Katarina Kysela, James A. Goodrich, James L. Lessard, Thomas J. Hope, Pavel Hozak, Primal de Lanerolle*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

309 Scopus citations


Actin is abundant in the nucleus and has been implicated in transcription; however, the nature of this involvement has not been established. Here we demonstrate that β-actin is critically involved in transcription because antibodies directed against β -actin, but not muscle actin, inhibited transcription in vivo and in vitro. Chromatin immunoprecipitation assays demonstrated the recruitment of actin to the promoter region of the interferon-γ-inducible MHC2TA gene as well as the interferon-α-inducible G1P3 gene. Further investigation revealed that actin and RNA polymerase II co-localize in vivo and also co-purify. We employed an in vitro system with purified nuclear components to demonstrate that antibodies to β -actin block the initiation of transcription. This assay also demonstrates that β-actin stimulates transcription by RNA polymerase II. Finally, DNA-binding experiments established the presence of β-actin in pre-initiation complexes and also showed that the depletion of actin prevented the formation of pre-initiation complexes. Together, these data suggest a fundamental role for actin in the initiation of transcription by RNA polymerase II.

Original languageEnglish (US)
Pages (from-to)1094-1101
Number of pages8
JournalNature Cell Biology
Issue number11
StatePublished - Nov 2004

ASJC Scopus subject areas

  • Cell Biology


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