Cancer Epidemiology Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA.
Sci Signal. 2012 Sep 18;5(242):rs6. doi: 10.1126/scisignal.2002255.
Eukaryotic cells have evolved an intricate system to resolve DNA damage to prevent its transmission to daughter cells. This system, collectively known as the DNA damage response (DDR) network, includes many proteins that detect DNA damage, promote repair, and coordinate progression through the cell cycle. Because defects in this network can lead to cancer, this network constitutes a barrier against tumorigenesis. The modular BRCA1 carboxyl-terminal (BRCT) domain is frequently present in proteins involved in the DDR, can exist either as an individual domain or as tandem domains (tBRCT), and can bind phosphorylated peptides. We performed a systematic analysis of protein-protein interactions involving tBRCT in the DDR by combining literature curation, yeast two-hybrid screens, and tandem affinity purification coupled to mass spectrometry. We identified 23 proteins containing conserved BRCT domains and generated a human protein-protein interaction network for seven proteins with tBRCT. This study also revealed previously unknown components in DNA damage signaling, such as COMMD1 and the target of rapamycin complex mTORC2. Additionally, integration of tBRCT domain interactions with DDR phosphoprotein studies and analysis of kinase-substrate interactions revealed signaling subnetworks that may aid in understanding the involvement of tBRCT in disease and DNA repair.
真核细胞进化出了一种复杂的系统来解决 DNA 损伤，以防止其传递给子细胞。这个系统，通常被称为 DNA 损伤反应（DDR）网络，包含许多能够检测 DNA 损伤、促进修复以及协调细胞周期进程的蛋白质。由于该网络的缺陷可能导致癌症，因此该网络构成了肿瘤发生的障碍。BRCA1 羧基末端（BRCT）结构域在参与 DDR 的蛋白质中经常存在，可以作为单个结构域或串联结构域（tBRCT）存在，并且可以结合磷酸化肽。我们通过结合文献整理、酵母双杂交筛选以及串联亲和纯化与质谱联用，对 DDR 中的 tBRCT 蛋白-蛋白相互作用进行了系统分析。我们鉴定了 23 个含有保守 BRCT 结构域的蛋白质，并生成了具有 tBRCT 的七个蛋白质的人类蛋白质-蛋白质相互作用网络。这项研究还揭示了 DNA 损伤信号中的先前未知成分，如 COMMD1 和雷帕霉素复合物 mTORC2 的靶标。此外，将 tBRCT 结构域相互作用与 DDR 磷酸化蛋白研究相结合，并分析激酶-底物相互作用，揭示了可能有助于理解 tBRCT 在疾病和 DNA 修复中的参与的信号转导子网络。
