The DNA damage response (DDR) is a complex signaling network that relies on cascades of protein phosphorylation, which are initiated by three protein kinases of the family of PI3‐kinase‐related protein kinases (PIKKs): ATM, ATR, and DNA‐PK. ATM is missing or inactivated in the genome instability syndrome, ataxia‐telangiectasia (A‐T). The relative shares of these PIKKs in the response to genotoxic stress and the functional relationships among them are central questions in the genome stability field. We conducted a comprehensive phosphoproteomic analysis in human wild‐type and A‐T cells treated with the double‐strand break‐inducing chemical, neocarzinostatin, and validated the results with the targeted proteomic technique, selected reaction monitoring. We also matched our results with 34 published screens for DDR factors, creating a valuable resource for identifying strong candidates for novel DDR players. We uncovered fine‐tuned dynamics between the PIKKs following genotoxic stress, such as DNA‐PK‐dependent attenuation of ATM. In A‐T cells, partial compensation for ATM absence was provided by ATR and DNA‐PK, with distinct roles and kinetics. The results highlight intricate relationships between these PIKKs in the DDR.

中文翻译：

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磷酸化蛋白质组学揭示了 PIKK 响应基因毒性应激的新功能模式和相互关系


DNA 损伤反应 (DDR) 是一个复杂的信号网络，依赖于蛋白质磷酸化级联，这些级联由 PI3 激酶相关蛋白激酶 (PIKK) 家族的三种蛋白激酶启动：ATM、ATR 和 DNA-PK 。在基因组不稳定综合征、共济失调毛细血管扩张症 (A-T) 中，ATM 缺失或失活。这些 PIKK 在基因毒性应激反应中的相对份额以及它们之间的功能关系是基因组稳定性领域的核心问题。我们对用双链断裂诱导化学品新制癌菌素处理的人类野生型和 A-T 细胞进行了全面的磷酸化蛋白质组学分析，并通过靶向蛋白质组学技术、选择性反应监测验证了结果。我们还将我们的结果与 34 个已发布的 DDR 因素屏幕进行了匹配，为识别新型 DDR 参与者的强大候选者创建了宝贵的资源。我们发现了基因毒性应激后 PIKK 之间的微调动态，例如 ATM 的 DNA PK 依赖性衰减。在 A-T 细胞中，ATR 和 DNA-PK 提供了对 ATM 缺失的部分补偿，具有不同的作用和动力学。结果凸显了 DDR 中这些 PIKK 之间错综复杂的关系。