Related Experiment Video
Updated: Oct 7, 2026

Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Expression of the cell cycle phosphatase cdc25C is down-regulated by the tumor suppressor protein p53 but not by p73
K Krause1, U Haugwitz, M Wasner
1Department of Internal Medicine II, University of Leipzig, Max Bürger Research Centre, Johannisallee 30, D-04103 Leipzig, Germany.
Abstract:
The cdc25C phosphatase dephosphorylates cdc2 kinase which then in complex with cyclin B can catalyse transition from the G(2) phase to mitosis. We demonstrate that transcription of cdc25C is repressed by p53 in a dose-dependent manner. In stably transfected DLD-1 colorectal adenocarcinoma cells, cdc25C expression is down-regulated when p53 is induced from a (tet)-off-regulated system. In contrast to p53, its homologue p73 is not able to down-modulate cdc25C expression. A previously identified site in the cdc25C promoter can bind p53 in vitro and, when placed in a heterologous construct, is able to activate transcription. However, transcriptional repression by p53 is not mediated through this site but is dependent on a segment containing three CCAAT-boxes. In general down-regulation of cdc25C transcription by reducing the levels of active cdc2 kinase contributes to G(2) arrest and G(2)/M checkpoint control. This reveals functional differences between p73 and p53 in regulating cell division.
Related Concept Videos
Abnormal Proliferation
Inhibition of Cdk Activity
Inhibition of CDK Activity
DNA Damage can Stall the Cell Cycle
DNA Damage Can Stall the Cell Cycle
Negative Regulator Molecules
