Lysines 3241 and 3260 of DNA-PKcs are important for genomic stability and radioresistance.
DNA-dependent protein kinase (DNA-PK) is a serine/threonine kinase that plays an essential role in the repair of DNA double-strand breaks (DSBs) in the non-homologous end-joining (NHEJ) pathway. The DNA-PK holoenzyme consists of a catalytic subunit (DNA-PKcs) and DNA-binding subunit (Ku70/80, Ku). Ku is a molecular sensor for double-stranded DNA and once bound to DSB ends it recruits DNA-PKcs to the DSB site. Subsequently, DNA-PKcs is activated and heavily phosphorylated, with these phosphorylations modulating DNA-PKcs. Although phosphorylation of DNA-PKcs is well studied, other post-translational modifications of DNA-PKcs are not. In this study, we aimed to determine if acetylation of DNA-PKcs regulates DNA-PKcs-dependent DSB repair. We report that DNA-PKcs is acetylated in vivo and identified two putative acetylation sites, lysine residues 3241 and 3260. Mutating these sites to block potential acetylation results in increased radiosensitive, a slight decrease in DSB repair capacity as assessed by γH2AX resolution, and increased chromosomal aberrations, especially quadriradial chromosomes. Together, our results provide evidence that acetylation potentially regulates DNA-PKcs.
Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, 2201 Inwood Rd, Dallas, TX 75390, United States; Department of Radiation Oncology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan.
Eiichiro
E
Mori
Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, 2201 Inwood Rd, Dallas, TX 75390, United States.
Anthony J
AJ
Davis
Department of Radiation Oncology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan.
Masatoshi
M
Hasegawa
Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas Southwestern Medical Center, 2201 Inwood Rd, Dallas, TX 75390, United States. Electronic address: David.Chen@UTSouthwestern.edu.
David J
DJ
Chen
D000818:Animals; D016466:CHO Cells; D003412:Cricetulus; D004247:DNA / Q000235:genetics* / Q000528:radiation effects; D004249:DNA Damage / Q000235:genetics*; D051747:DNA-Activated Protein Kinase / Q000235:genetics* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004706:Endodeoxyribonucleases; D029968:Escherichia coli Proteins; D042822:Genomic Instability / Q000235:genetics* / Q000528:radiation effects*; D008239:Lysine / Q000235:genetics / Q000528:radiation effects; D009687:Nuclear Proteins / Q000235:genetics* / Q000528:radiation effects; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000235:genetics*; D013329:Structure-Activity Relationship
D029968:Escherichia coli Proteins; D009687:Nuclear Proteins; D004247:DNA; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D004706:Endodeoxyribonucleases; C448636:Cho protein, E coli; D008239:Lysine
Acetylation; DNA double-strand breaks; DNA-PKcs; Non-homologous end-joining