ADP-核糖基化 (ADPr) 信号在 DNA 损伤反应中发挥着至关重要的作用。 DNA 损伤后催化 ADPr 的主要酶聚（ADP-核糖）聚合酶 1 (PARP1) 的抑制剂用于治疗携带 BRCA1/2 突变的乳腺癌患者。然而，对 PARP 抑制剂（PARPi）的耐药性是治疗患者的主要障碍。为了了解 ADPr 在 PARPi 敏感性中的作用，我们使用液相色谱-串联质谱 (LC-MS/MS) 分析了表现出不同 PARPi 敏感性的六种乳腺癌细胞系中的 ADPr。我们在所有细胞系的 777 个蛋白质上鉴定了 1,632 个位点，主要是丝氨酸残基，所有细胞系中 DNA 损伤相关蛋白质的目标残基有位点特异性重叠，证明了 DNA 损伤时丝氨酸 ADPr 信号网络的高度保守性。此外，我们观察到 PARPi 敏感 BRCA 突变体中 ADPr 强度的位点特异性差异，以及 PARPi 抗性 BRCA 突变体 HCC1937 细胞中独特的 ADPr 位点，这些细胞具有低聚（ADP-核糖）糖水解酶（PARG）水平和较长的 ADPr 链。 PARP1.版权所有 © 2024 作者。由爱思唯尔公司出版。保留所有权利。

ADP-ribosylation (ADPr) signaling plays a crucial role in DNA damage response. Inhibitors against the main enzyme catalyzing ADPr after DNA damage, poly(ADP-ribose) polymerase 1 (PARP1), are used to treat patients with breast cancer harboring BRCA1/2 mutations. However, resistance to PARP inhibitors (PARPi) is a major obstacle in treating patients. To understand the role of ADPr in PARPi sensitivity, we use liquid chromatography-tandem mass spectrometry (LC-MS/MS) to analyze ADPr in six breast cancer cell lines exhibiting different PARPi sensitivities. We identify 1,632 sites on 777 proteins across all cell lines, primarily on serine residues, with site-specific overlap of targeted residues across DNA-damage-related proteins across all cell lines, demonstrating high conservation of serine ADPr-signaling networks upon DNA damage. Furthermore, we observe site-specific differences in ADPr intensities in PARPi-sensitive BRCA mutants and unique ADPr sites in PARPi-resistant BRCA-mutant HCC1937 cells, which have low poly(ADP-ribose) glycohydrolase (PARG) levels and longer ADPr chains on PARP1.Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.