USP13 regulates the replication stress response by deubiquitinating TopBP1

Area of Science:

• Molecular Biology
• Cell Biology
• Genomics

Background:

• The DNA replication stress-induced checkpoint, mediated by the TopBP1-ATR pathway, is vital for genomic stability.
• The precise regulation of TopBP1 during DNA damage responses is not fully understood.

Purpose of the Study:

• To identify novel regulators of TopBP1 in DNA damage response.
• To elucidate the role of USP13 in the TopBP1-ATR axis and its implications in cancer.

Main Methods:

• Biochemical assays to determine USP13-TopBP1 interaction and deubiquitination activity.
• Cell-based assays to assess the impact of USP13 depletion on ATR activation and cellular response to replication stress.
• Analysis of USP13 expression in cancer patient cohorts and correlation with clinical outcomes.

Main Results:

• USP13 was identified as a deubiquitinating enzyme that binds to and stabilizes TopBP1.
• Depletion of USP13 impaired ATR activation and increased cellular sensitivity to replication-inducing agents.
• High USP13 expression correlated with enhanced replication stress response, increased cancer cell chemoresistance, and poorer patient prognosis.

Conclusions:

• USP13 is a novel deubiquitinating enzyme for TopBP1, playing a key role in coordinating the replication stress response.
• USP13's function in stabilizing TopBP1 has significant implications for cancer cell survival and chemoresistance, suggesting its potential as a therapeutic target.