Evidence that Mediator is essential for Pol II transcription, but is not a required component of the preinitiation complex in vivo

  1. Natalia Petrenko
  2. Yi Jin
  3. Koon Ho Wong
  4. Kevin Struhl  Is a corresponding author
  1. Harvard Medical School, United States
  2. University of Macau, China

Abstract

The Mediator complex has been described as a general transcription factor, but it is unclear if it is essential for Pol II transcription and/or is a required component of the preinitiation complex (PIC) in vivo. Here, we show that depletion of individual subunits, even those essential for cell growth, causes a general but only modest decrease in transcription. In contrast, simultaneous depletion of all Mediator modules causes a drastic decrease in transcription. Depletion of head or middle subunits, but not tail subunits, causes a downstream shift in the Pol II occupancy profile, suggesting that Mediator at the core promoter inhibits promoter escape. Interestingly, a functional PIC and Pol II transcription can occur when Mediator is not detected at core promoters. These results provide strong evidence that Mediator is essential for Pol II transcription and stimulates PIC formation, but it is not a required component of the PIC in vivo.

Data availability

The following data sets were generated
The following previously published data sets were used
    1. Paul et al.
    (2015) Saccharomyces cerevisiae S288c Genome sequencing
    Publicly available via DNA Data Bank of Japan (accession no. SRP047524).

Article and author information

Author details

  1. Natalia Petrenko

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
    Competing interests
    No competing interests declared.
  2. Yi Jin

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
    Competing interests
    No competing interests declared.
  3. Koon Ho Wong

    Faculty of Health Sciences, University of Macau, Zhuhai Shi, China
    Competing interests
    No competing interests declared.
  4. Kevin Struhl

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
    For correspondence
    kevin@hms.harvard.edu
    Competing interests
    Kevin Struhl, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4181-7856

Funding

National Institutes of Health (GM 30186)

  • Kevin Struhl

Croucher Foundation

  • Koon Ho Wong

University of Macau (MYRG2015-00186-FHS)

  • Koon Ho Wong

University of Macau (MYRG2016-0-0211-FHS)

  • Koon Ho Wong

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2017, Petrenko et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Natalia Petrenko
  2. Yi Jin
  3. Koon Ho Wong
  4. Kevin Struhl
(2017)
Evidence that Mediator is essential for Pol II transcription, but is not a required component of the preinitiation complex in vivo
eLife 6:e28447.
https://doi.org/10.7554/eLife.28447

Share this article

https://doi.org/10.7554/eLife.28447

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