Structure-based rescue of common tumor-derived p53 mutants

Area of Science:

• Molecular Biology
• Cancer Research
• Protein Biochemistry

Background:

• The p53 protein is crucial for tumor suppression, halting cell-cycle progression or inducing cell death upon DNA damage.
• Mutations in the p53 DNA binding domain occur in half of human cancers, compromising its tumor suppressor function.
• The nature of p53 mutations raises questions about the potential for rescuing its activity.

Purpose of the Study:

• To investigate whether tumor-derived p53 mutants can be reactivated to restore tumor suppressor functions.
• To explore strategies for rescuing p53 function by modifying its DNA binding domain.

Main Methods:

• Engineered novel contacts within the p53 DNA binding domain by introducing basic residues.
• Targeted specific amino acid substitutions, notably Thr284 to Arg, in common p53 mutants.
• Assessed DNA binding affinity, specificity, and transactivation activity of modified p53 mutants.

Main Results:

• Replacement of Thr284 with Arg significantly enhanced DNA binding affinity in three out of seven common p53 mutants.
• The introduced modifications did not compromise the sequence-specific DNA binding of p53.
• Rescued transactivation and tumor suppressor functions were observed in the modified p53 mutants.

Conclusions:

• Many tumor-derived p53 mutants retain their capacity for sequence-specific DNA binding.
• Reactivating p53 mutants through targeted modifications can restore their tumor suppressor activity.
• This approach holds promise for developing novel cancer therapeutics that specifically target cancer cells with p53 mutations.