Budding yeast DNA damage adaptation mutants exhibit defects in mitotic exit

Area of Science:

• Cell biology
• Molecular genetics
• DNA damage response

Background:

• DNA damage checkpoints halt cell cycle progression upon double-strand breaks.
• Cells typically adapt and re-enter the cell cycle, even with irreparable DNA damage.
• The cdc5-ad mutant exhibits a failure to adapt to DNA damage checkpoint arrest.

Purpose of the Study:

• To investigate if the adaptation defect in cdc5-ad mutant cells is related to the function of Cdc5 in mitotic exit.
• To explore the role of the mitotic exit pathway in DNA damage adaptation.

Main Methods:

• Characterization of cdc5-ad mutant sensitivity to Amn1, a negative regulator of the MEN pathway.
• Analysis of synthetic growth defects in cdc5-ad mutants combined with MEN pathway mutants.
• Assessment of DNA damage adaptation in mutants of the FEAR pathway.

Main Results:

• cdc5-ad mutant cells show defects in mitotic exit.
• These cells are sensitive to high doses of Amn1 and exhibit synthetic growth defects with MEN pathway mutants.
• Mutants in the FEAR pathway also display defects in DNA damage adaptation.

Conclusions:

• The mitotic exit pathway, involving MEN and FEAR, is crucial for DNA damage adaptation.
• Compromised mitotic exit contributes to the DNA damage adaptation defects observed in cdc5-ad mutant cells.