A precisely adjustable, variation-suppressed eukaryotic transcriptional controller to enable genetic discovery

  1. Asli Azizoglu  Is a corresponding author
  2. Roger Brent  Is a corresponding author
  3. Fabian Rudolf  Is a corresponding author
  1. ETH Zurich, Switzerland
  2. Fred Hutchinson Cancer Research Center, United States


Conditional expression of genes and observation of phenotype remain central to biological discovery. Current methods enable either on/off or imprecisely controlled graded gene expression. We developed a 'well-tempered' controller, WTC846, for precisely adjustable, graded, growth condition independent expression of genes in Saccharomyces cerevisiae. Controlled genes are expressed from a strong semisynthetic promoter repressed by the prokaryotic TetR, which also represses its own synthesis; with basal expression abolished by a second, 'zeroing' repressor. The autorepression loop lowers cell-to-cell variation while enabling precise adjustment of protein expression by a chemical inducer. WTC846 allelic strains in which the controller replaced the native promoters recapitulated known null phenotypes (CDC42, TPI1), exhibited novel overexpression phenotypes (IPL1), showed protein dosage-dependent growth rates and morphological phenotypes (CDC28, TOR2, PMA1 and the hitherto uncharacterized PBR1), and enabled cell cycle synchronization (CDC20). WTC846 defines an 'expression clamp' allowing protein dosage to be adjusted by the experimenter across the range of cellular protein abundances, with limited variation around the setpoint.

Data availability

All relevant sequences are included in the supporting files for reproducibility. All raw flow cytometry data is publicly available at doi.org/10.3929/ethz-b-000488967. All other source data is included in the manuscript and supporting files.

Article and author information

Author details

  1. Asli Azizoglu

    BSSE, ETH Zurich, Basel, Switzerland
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
  2. Roger Brent

    Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8398-3273
  3. Fabian Rudolf

    D-BSSE, ETH Zurich, Basel, Switzerland
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.


Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (NCCR Molecular Systems Engineering)

  • Asli Azizoglu
  • Fabian Rudolf

National Cancer Institute (R21CA223901)

  • Roger Brent

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

Reviewing Editor

  1. Naama Barkai, Weizmann Institute of Science, Israel

Publication history

  1. Received: April 19, 2021
  2. Accepted: August 2, 2021
  3. Accepted Manuscript published: August 3, 2021 (version 1)
  4. Version of Record published: September 6, 2021 (version 2)


© 2021, Azizoglu 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. Asli Azizoglu
  2. Roger Brent
  3. Fabian Rudolf
A precisely adjustable, variation-suppressed eukaryotic transcriptional controller to enable genetic discovery
eLife 10:e69549.

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