Disordered regions mediate the interaction of p53 and MRE11

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Genotoxic agents cause DNA damage, necessitating robust cellular repair mechanisms.
• The Mre11-Rad50-Nbs1 complex and ATM kinase are key players in detecting and responding to DNA double-strand breaks (DSBs).
• p53 tumor suppressor, regulated by ATM, controls critical cellular processes post-DNA damage.

Purpose of the Study:

• To identify the specific domains involved in the interaction between p53 and MRE11.
• To investigate how post-translational modifications (PTMs) regulate the p53-MRE11 interaction.
• To elucidate the molecular mechanisms underlying p53-MRE11 complex formation at DNA damage sites.

Main Methods:

• Utilized biophysical techniques to study protein interactions in vitro.
• Investigated the binding domains of p53 and MRE11.
• Assessed the impact of phosphorylation and methylation on p53-MRE11 binding.

Main Results:

• p53 directly binds to the MRE11 glycine-arginine-rich (GAR) domain, primarily via p53's TAD2 region.
• Phosphorylation of p53 enhances its interaction with MRE11^GAR.
• Methylation of MRE11^GAR does not prevent binding to p53, indicating complex regulation.

Conclusions:

• The interaction between p53 and MRE11 is mediated by their intrinsically disordered regions.
• PTMs, including phosphorylation and methylation, play a significant role in regulating the p53-MRE11 interaction.
• These findings provide novel insights into the molecular basis of the DNA damage response and potential colocalization to PML-NBs.