Dual contributions of Xrp1 to genome integrity through the DNA damage response and cell competition.

Xrp1 contributes to genome integrity in Drosophila through both p53-dependent DNA damage response and p53-independent cell competition mechanisms, especially after irradiation.

• Why it matters: Understanding how p53 suppresses tumor formation is crucial, as it plays a key role in maintaining genome stability. The mechanisms involving Xrp1 may reveal new insights into tumor suppression pathways.
• What they did: Researchers examined Xrp1's functions in Drosophila, showing it mediates p53-dependent gene transcription and apoptosis during DNA damage, and is induced by RpS12 in p53-independent cell competition, especially after irradiation.
• The result: Xrp1 limits the accumulation of damaged cells via both immediate DNA damage responses and later cell competition, suggesting it may be a vital component of p53's tumor suppressor activity in mammals.