Basal dynamics of p53 reveal transcriptionally attenuated pulses in cycling cells

Alexander Loewer ¹, Eric Batchelor , Giorgio Gaglia

⁰Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.

Cell +

|

July 6, 2010

View abstract on PubMed

Summary

The tumor suppressor p53 pathway exhibits excitable pulses in proliferating cells, balancing sensitivity to DNA damage with tolerance to transient issues. This prevents inappropriate cell-cycle arrest during normal growth.

Area Of Science

Cellular biology
Molecular oncology
Genetics

Background

The tumor suppressor p53 is crucial for cellular responses to stress, including apoptosis and cell-cycle arrest.
High sensitivity of p53 activation is essential for appropriate cellular damage response.
Proliferating cells face transient DNA damage, where cell-cycle arrest or apoptosis can be detrimental.

Purpose Of The Study

To investigate how the p53 pathway achieves a balance between high sensitivity and tolerance to intrinsic DNA damage in proliferating cells.
To understand the dynamic behavior of p53 in response to cellular stress and normal growth conditions.

Main Methods

Quantitative time-lapse microscopy was employed to monitor individual human cells.
The study focused on quantifying basal dynamics of the p53 pathway in a noisy cellular environment.

Main Results

Proliferating cells exhibit spontaneous pulses of p53, driven by an excitable mechanism during cell-cycle phases with intrinsic DNA damage.
Posttranslational modifications maintain p53 inactivity in the absence of sustained damage, preventing p21 expression and cell-cycle arrest.
A method for quantifying basal pathway dynamics in individual cells was developed.

Conclusions

The p53 pathway utilizes an excitable mechanism to generate transient p53 pulses, allowing for sensitivity to DNA damage while tolerating normal cellular noise.
This dynamic regulation prevents unnecessary cell-cycle arrest, crucial for efficient cell proliferation.
The quantitative approach can be applied to study other sensitive pathways in complex cellular environments.

Related Concept Videos