p53 and cell-cycle control: a finger in every pie

Area of Science:

• Molecular Biology
• Cell Biology
• Genetics

Background:

• The p53 protein is crucial for cellular responses to stress, including DNA damage.
• Its roles in cell cycle control are not fully understood, despite evidence for its involvement in apoptosis.

Purpose of the Study:

• To review the cell-cycle-dependent regulation of p53 expression, protein levels, and activity.
• To summarize p53's involvement in controlling progression through G1, S, G2, and M phases.
• To discuss how cell-cycle regulation impacts p53 activity and levels during the normal cell cycle.

Main Methods:

• Review of existing in vitro and in vivo data.
• Analysis of transcriptional control, protein stability, and post-translational modifications (phosphorylation, acetylation, conformation).

Main Results:

• p53 expression, protein levels, and activity are modulated in a cell-cycle-dependent manner.
• p53 directly or indirectly influences progression through all phases of the cell cycle (G1, S, G2, M).
• Permanent cell-cycle arrest is proposed as a stress response in cells with limited proliferative potential.

Conclusions:

• p53 plays a significant role in cell cycle control, maintaining genetic and tissue integrity.
• Cell-cycle regulation is a key mechanism for controlling p53 protein levels and activity.
• Understanding p53's cell cycle functions is vital for comprehending cellular responses to stress.