Chk1 kinase negatively regulates mitotic function of Cdc25A phosphatase through 14-3-3 binding.

Article Details

Citation

Chen MS, Ryan CE, Piwnica-Worms H

Chk1 kinase negatively regulates mitotic function of Cdc25A phosphatase through 14-3-3 binding.

Mol Cell Biol. 2003 Nov;23(21):7488-97.

PubMed ID
14559997 [ View in PubMed
]
Abstract

The order and fidelity of cell cycle events in mammals is intimately linked to the integrity of the Chk1 kinase-Cdc25A phosphatase pathway. Chk1 phosphorylation targets Cdc25A for destruction and, as shown here, inhibits interactions between Cdc25A and its mitotic substrate cyclin B1-Cdk1. Phosphorylation of Cdc25A on serine 178 and threonine 507 facilitates 14-3-3 binding, and Chk1 phosphorylates both residues in vitro. Mutation of T507 to alanine (T507A) enhanced the biological activity of Cdc25A. Cdc25A(T507A) was more efficient in binding to cyclin B1, activating cyclin B1-Cdk1, and promoting premature entry into mitosis. We propose that the Chk1/Cdc25A/14-3-3 pathway functions to prevent cells from entering into mitosis prior to replicating their genomes to ensure the fidelity of the cell division process.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Serine/threonine-protein kinase Chk1O14757Details