Distinct p53 acetylation cassettes differentially influence gene-expression patterns and cell fate

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• The tumor suppressor protein p53 is regulated by numerous posttranslational modifications.
• It remains unclear whether these modifications function independently or coordinately.

Purpose of the Study:

• To investigate the functional interplay between distinct posttranslational modifications of p53.
• To determine how these modifications influence p53 activity and downstream cellular responses.

Main Methods:

• Analysis of specific acetylation and phosphorylation sites on p53.
• Assessment of p53 binding to DNA and interaction with cofactors.
• Evaluation of gene expression profiles and cell fate determination.

Main Results:

• Acetylation at K320 inhibits NH(2)-terminal phosphorylation, favoring survival gene activation and cell survival.
• Acetylation at K373 promotes NH(2)-terminal hyperphosphorylation, enhancing proapoptotic gene activation and cell death.
• Differential acetylation patterns lead to distinct gene expression profiles and cofactor interactions.

Conclusions:

• Posttranslational modifications on p53 exhibit functional interference, influencing cell fate decisions.
• A "p53 code" model, analogous to the "histone code," is proposed, where specific patterns of modifications and interactions orchestrate p53 activity.