The MDM2/MDMX/p53 axis in the adaptive stress response

Area of Science:

• Cellular biology
• Molecular oncology
• Stress response pathways

Background:

• The p53 protein (also known as TP53) is a key regulator of cellular stress responses, traditionally recognized for its role in inducing cell death.
• Emerging evidence suggests p53 also plays a crucial role in promoting cell survival through adaptive stress responses.

Purpose of the Study:

• To elucidate the dual role of p53 in cellular stress, encompassing both pro-death and pro-survival functions.
• To investigate the relationship between adaptive stress responses, p53 dynamics, and the maintenance of cellular homeostasis.

Main Methods:

• Review and synthesis of existing literature on p53 function in cellular stress.
• Analysis of the impact of stress intensity and duration on p53 activity and abundance.
• Modeling of p53-mediated cell fate determination under varying stress conditions.

Main Results:

• Adaptive stress responses are linked to a transient decline in p53 levels, which is necessary for activating pro-survival pathways.
• Persistent or chronic adaptive stress responses can lead to sustained downregulation of p53.
• This sustained p53 loss results in impaired homeostasis and a permanent deficit in p53-dependent functions.

Conclusions:

• Cellular fate decisions under stress are governed by the interplay between stress levels, stress duration, and p53 regulation.
• The dynamic regulation of p53 abundance and activity is critical for balancing cell survival and death.
• Chronic stress-induced p53 downregulation poses a risk to cellular homeostasis and function.