Related Experiment Videos
Preferential binding of ATR protein to UV-damaged DNA
Keziban Unsal-Kaçmaz1, Alexander M Makhov, Jack D Griffith
1Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
Abstract:
The ATR protein is a member of the phosphoinositide 3-kinase-related kinase family and plays an important role in UV-induced DNA damage checkpoint response. Its role as a signal transducer in cell cycle checkpoint is well established, but it is currently unclear whether ATR functions as a damage sensor as well. Here we have purified the ATR protein and investigated its interaction with DNA by using biochemical analysis and electron microscopy. We find that ATR is a DNA-binding protein with higher affinity to UV-damaged than undamaged DNA. In addition, damaged DNA stimulates the kinase activity of ATR to a significantly higher level than undamaged DNA. Our data suggest that ATR may function as an initial sensor in the DNA damage checkpoint response.
Insights
The ATR protein binds to UV-damaged DNA and becomes more active, suggesting it acts as an initial sensor in DNA damage response pathways. This finding clarifies ATR's role in the UV-induced DNA damage checkpoint.
Area of Science:
- Molecular Biology
- Cellular Biology
- Biochemistry
Background:
- The ATR protein, a PI3K-related kinase, is crucial for UV-induced DNA damage checkpoint response.
- ATR's function as a signal transducer in cell cycle checkpoints is known, but its role as a damage sensor is unclear.
Purpose of the Study:
- To investigate the interaction between the ATR protein and DNA.
- To determine if ATR functions as a DNA damage sensor.
Main Methods:
- Purification of the ATR protein.
- Biochemical analysis of ATR-DNA interaction.
- Electron microscopy of ATR-DNA complexes.
Main Results:
- ATR exhibits DNA-binding properties.
- ATR demonstrates higher affinity for UV-damaged DNA compared to undamaged DNA.
- Damaged DNA significantly enhances ATR's kinase activity.
Conclusions:
- ATR functions as a DNA-binding protein.
- The findings suggest ATR may act as an initial sensor in the DNA damage checkpoint response.
- ATR's dual role as a sensor and transducer in DNA damage response is indicated.