Preferential Binding of ATR Protein to UV-Damaged DNA

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 99; no. 10; pp. 6673 - 6678
• Main Authors: Ünsal-Kaçmaz, Keziban, Makhov, Alexander M., Griffith, Jack D., Sancar, Aziz
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 14.05.2002; National Acad Sciences; The National Academy of Sciences
• Subjects: Ataxia Telangiectasia Mutated Proteins; ATR protein; Biochemistry; Biological Sciences; Cell cycle; Cell Cycle Proteins - genetics; Cell Cycle Proteins - isolation & purification; Cell Cycle Proteins - metabolism; Cell Line, Transformed; Deoxyribonucleic acid; DNA; DNA - metabolism; DNA - radiation effects; DNA - ultrastructure; DNA Damage; DNA-Binding Proteins - genetics; DNA-Binding Proteins - isolation & purification; DNA-Binding Proteins - metabolism; HEK293 cells; Humans; Lesions; Microscopy, Electron; Oligodeoxyribonucleotides - metabolism; Peptide Fragments - genetics; Peptide Fragments - isolation & purification; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - isolation & purification; Protein-Serine-Threonine Kinases - metabolism; Proteins; Radiation damage; Sensors; Silver staining; Studies; Tumor Suppressor Protein p53 - metabolism; Ultraviolet radiation; Ultraviolet Rays
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.102167799

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.