Related Experiment Video

Updated: Aug 19, 2026

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins
10:24

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins

Published on: September 28, 2012

Modulation of p53 binding to Holliday junctions and 3-cytosine bulges by phosphorylation events

Deepa Subramanian1, Jack D Griffith

  • 1Lineberger Comprehensive Cancer Center and Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7295, USA.

Biochemistry
|February 16, 2005
PubMed

Insights

Phosphorylation regulates tumor suppressor p53’s DNA binding. Dephosphorylating serine 392 impairs lesion recognition, while rephosphorylation restores it, highlighting the critical role of p53’s phosphorylation state in DNA damage response.

Area of Science:

  • Molecular Biology
  • Biochemistry
  • Genetics

Background:

  • The tumor suppressor protein p53 plays a crucial role in DNA damage response.
  • p53's DNA binding function is modulated by post-translational modifications, particularly phosphorylation.
  • Stress-response kinases activate p53, enhancing its stability and transactivation capabilities.

Purpose of the Study:

  • To investigate how phosphorylation events impact the sequence-independent DNA binding of p53.
  • To determine the specific roles of serine 392 and other phosphorylation sites in p53's DNA binding to various substrates.

Main Methods:

  • Utilized gel retardation assays to assess p53 binding to DNA substrates.
  • Examined DNA substrates resembling Holliday junctions and those with extra base bulges.
  • Investigated the effects of dephosphorylation and rephosphorylation at specific sites on p53.

Main Results:

  • Dephosphorylation of serine 392 significantly diminished p53's recognition of Holliday junctions and DNA lesions.
  • Removal of N-terminal phosphates disrupted sequence-specific binding, but not serine 392.
  • Rephosphorylation by kinases restored p53's ability to recognize Holliday junctions and 3-cytosine bulges, involving serine 392 and other residues.

Conclusions:

  • p53's DNA binding activity is dynamically regulated by its phosphorylation status.
  • Serine 392 phosphorylation is critical for sequence-independent DNA binding and lesion recognition.
  • Multiple phosphorylation sites contribute to the reactivation of p53 DNA binding functions.

More Related Videos

Yeast As a Chassis for Developing Functional Assays to Study Human P5314:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

Purification of Ubiquitinated p53 Proteins from Mammalian Cells10:55

Purification of Ubiquitinated p53 Proteins from Mammalian Cells

Published on: March 21, 2022

Related Concept Videos

Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
DNA Damage can Stall the Cell Cycle02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
DNA Damage Can Stall the Cell Cycle02:36

DNA Damage Can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.