Related Experiment Video

Updated: May 26, 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

Structural delineation of MDC1-FHA domain binding with CHK2-pThr68

Hsin-Hui Wu1, Pei-Yu Wu, Kai-Fa Huang

  • 1Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan.

Biochemistry
|January 4, 2012
PubMed

Insights

The study reveals the crystal structure of Mammalian MDC1-FHA, an intrinsic dimer, and its complex with CHK2 peptide. This provides structural insight into the DNA damage response pathway and MDC1-CHK2 interaction.

Area of Science:

  • Molecular Biology
  • Structural Biology
  • Biochemistry

Background:

  • Mammalian MDC1 (Mediator of DNA-damage checkpoint 1) plays a role in DNA damage response.
  • MDC1 interacts with CHK2 (Checkpoint Kinase 2) to regulate the S-phase checkpoint and apoptosis.
  • This interaction is mediated by the FHA (Forkhead-Associated) domain of MDC1 binding to phosphorylated CHK2 (pThr68), but its structural basis and ligand specificity were unclear.

Purpose of the Study:

  • To determine the crystal structure of the MDC1-FHA domain.
  • To elucidate the structural basis of the interaction between MDC1-FHA and CHK2-pThr68.
  • To investigate the ligand specificity of the MDC1-FHA domain.

Main Methods:

  • X-ray crystallography was used to determine the structure of MDC1-FHA alone and in complex with a CHK2 peptide.
  • Structural analysis of the obtained crystal structures.
  • Binding assays to confirm ligand specificity.

Main Results:

  • The crystal structures of MDC1-FHA and its complex with a CHK2 peptide containing pThr68 were determined.
  • MDC1-FHA was found to exist as an intrinsic dimer in solution and in crystals, unlike other FHA domains.
  • Structural and binding analyses revealed a pThr+3 ligand specificity for MDC1-FHA.

Conclusions:

  • The study provides the first structural insights into the MDC1-FHA domain and its interaction with CHK2.
  • The dimeric nature of MDC1-FHA is a novel characteristic.
  • The findings clarify the molecular mechanism underlying MDC1-CHK2 interaction in the DNA damage response pathway.

More Related Videos

Single-Molecule Imaging of EWS-FLI1 Condensates Assembling on DNA07:05

Single-Molecule Imaging of EWS-FLI1 Condensates Assembling on DNA

Published on: September 8, 2021

Visualization of DNA Repair Proteins Interaction by Immunofluorescence07:55

Visualization of DNA Repair Proteins Interaction by Immunofluorescence

Published on: June 26, 2020

Related Concept Videos

Restarting Stalled Replication Forks02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
Separation of Sister Chromatids02:17

Separation of Sister Chromatids

At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
Assembly of Signaling Complexes01:30

Assembly of Signaling Complexes

Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
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...
Anaphase Promoting Complex00:50

Anaphase Promoting Complex

The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...