The ATR-WEE1 kinase module inhibits the MAC complex to regulate replication stress response

Area of Science:

• Plant molecular biology
• Cell cycle regulation
• DNA damage response

Background:

• Genome stability is maintained by DNA damage response pathways.
• The ATR-WEE1 kinase module is crucial for responding to replication stress.
• The function of the ATR-WEE1 pathway in plants is not well understood.

Purpose of the Study:

• To elucidate the role of the ATR-WEE1 pathway in plant replication stress response.
• To identify downstream components regulated by ATR-WEE1 in plants.
• To uncover novel mechanisms controlling cell cycle progression under stress.

Main Methods:

• Genetic screening of Arabidopsis mutants.
• Biochemical assays including protein interaction and phosphorylation studies.
• Analysis of gene expression, intron retention, and phenotypic rescue experiments.

Main Results:

• Loss of PRL1 function suppresses hypersensitivity in atr and wee1 mutants.
• WEE1 phosphorylates PRL1, promoting its degradation.
• Replication stress induces intron retention of cell cycle genes, regulated by WEE1 and PRL1.

Conclusions:

• The ATR-WEE1 module inhibits the MAC complex (including PRL1) to control replication stress responses.
• PRL1 and the MAC complex are key downstream regulators of the ATR-WEE1 module in plants.
• A novel mechanism for cell cycle control during replication stress involving alternative splicing is revealed.