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Updated: Aug 23, 2026

Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
p53-dependent transcription can exhibit both on/off and graded response after genotoxic stress
Arvi Jõers1, Viljar Jaks, Johanna Kase
1Department of Cell Biology, Institute of Molecular and Cell Biology, Tartu University, Riia 23, 51010, Tartu, Estonia. ajoers@ebc.es
Abstract:
The p53 protein is a central player in cellular response to DNA damage. Induction of p53 by DNA-damaging agents involves elevation of its steady-state level and activation of its potency as a transcription factor. In the cell population, these responses can occur either homogeneously (where every single cell responds simultaneously and similarly to its neighbor) or heterogeneously (where only some cells of a population respond and the number of these increases with increasing dose of inducer). We have studied here the p53 response to DNA-damaging agents (camptothecin, mitomycin C) in individual cells. We show that the level of p53 protein is increased in every single cell of the population homogeneously, while the p53-dependent transcription can be subject to an on/off-type response. Depending on the structure of the target promoter, p53-dependent transcription can be regulated according to the binary or graded model. The on/off-type transcriptional activation pattern of p53 defines two distinct subpopulations of cells after DNA damage.
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