ID4 regulates transcriptional activity of wild type and mutant p53 via K373 acetylation

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Mutated p53 is over-expressed in 50% of human cancers, making its restoration a key therapeutic target.
• Previous strategies to restore wild-type p53 function involved small molecules and peptides.
• Emerging research focuses on physiological mechanisms like acetylation to reactivate mutant p53.

Purpose of the Study:

• To investigate the role of ID4-dependent acetylation in restoring mutant p53's wild-type biological function.
• To elucidate the specific acetylation sites on p53 involved in this reactivation process.

Main Methods:

• Utilized a p53 null prostate cancer cell line.
• Employed wild-type p53, various mutant p53 forms (P223L, V274F, R175H, R273H), and acetylation mimic/non-mimic constructs (K320Q/K373Q and K320R/K373R).
• Assessed ID4's effect on p53 DNA-binding, target gene regulation, cell cycle arrest, and apoptosis.

Main Results:

• ID4 promotes the acetylation of p53, particularly at lysine 373 (K373) and to a lesser extent at K320.
• This ID4-mediated acetylation enhances mutant p53's DNA-binding capability to its wild-type consensus sequence.
• Restored p53 activity leads to the regulation of p53-dependent target genes, inducing cell cycle arrest and apoptosis.

Conclusions:

• ID4-dependent acetylation is a critical mechanism for restoring mutant p53's tumor-suppressive functions.
• Targeting p53 acetylation at K373 and K320 presents a potential physiological strategy for cancer therapy.
• This study provides molecular insights into ID4's role in p53 reactivation.