p53 pulse modulation differentially regulates target gene promoters to regulate cell fate decisions

Area of Science:

• Molecular Biology
• Cell Biology
• Biophysics

Background:

• The p53 tumor suppressor protein plays a critical role in cellular stress responses.
• Different cellular stresses induce distinct p53 protein dynamics (pulsing behavior).
• Mechanisms by which cells interpret these p53 dynamics to regulate specific target genes remain unclear.

Purpose of the Study:

• To investigate how individual cells respond to varying features of p53 protein dynamics.
• To determine how canonical p53 target gene promoters differ in their responsiveness to p53 signaling.
• To elucidate the signal processing mechanisms cells use to decode p53 dynamics.

Main Methods:

• Utilized a chemical perturbation approach to independently modulate p53 pulse amplitude, duration, and frequency in individual cells.
• Monitored intracellular p53 protein levels and target promoter activation in real-time within single cells.
• Analyzed promoter responses to specific p53 dynamic features.

Main Results:

• Identified distinct signal processing features: thresholding for amplitude, a refractory period for duration, and dynamic filtering for frequency modulation of p53.
• Demonstrated that these signal processing features directly impact p53 target promoter activation.
• Showed that promoter responses influence overall p53 regulation and downstream cellular functions.

Conclusions:

• Canonical p53 target gene promoters differentially decode features of p53 protein dynamics through specific signal processing mechanisms.
• Understanding these decoding mechanisms provides insight into how p53 dynamics dictate distinct cellular responses and cell fates.
• Perturbing p53 dynamics offers a potential strategy for manipulating cell fate decisions.