Single molecule studies of the interplay between DNA repair mechanisms and between DNA repair and DNA replication and transcription

DNA的稳定性不断受到化学和物理上的威胁，导致DNA的结构改变或化学修饰，从而导致癌症、细胞衰老或细胞凋亡。不同的DNA修饰由许多DNA修复机制修复，这些机制根据其特定的靶病变进行微调。最近的几项研究也指出了不同DNA修复系统之间的相互作用，以及DNA修复与DNA转录和复制之间的相互作用。我们计划研究直接损伤逆转DNA烷基转移酶和碱基切除修复(BER)糖基酶与核苷酸切除修复(NER)系统中的蛋白质之间的相互作用。烷基转移酶和糖基酶分别通过转录停滞或转录偶联的NER或全球基因组NER中蛋白质-蛋白质的直接相互作用来启动NER。烷基转移酶也被证明与参与DNA复制启动的蛋白质相互作用。我们的单分子成像方法使用原子力显微镜(AFM)和荧光光钳，一方面结合整体生物物理和功能生化分析，另一方面进行结晶研究，旨在提供对这些基本重要的DNA处理系统之间相互作用的机械洞察。

The stability of DNA is constantly chemically and physically threatened, resulting in structurally altered or chemically modified DNA that can lead to cancer, cell senescence, or apoptosis. Different DNA modifications are repaired by a number of DNA repair mechanisms that are fine-tuned to their particular target lesions. Several recent studies have also pointed at interactions between different DNA repair systems as well as between DNA repair and DNA transcription and replication. We plan to investigate the interplay of direct damage reversal DNA alkyltransferases and base excision repair (BER) glycosylases with proteins from the nucleotide excision repair (NER) system. Initiation of NER by alkyltransferases and glycosylases may be achieved via stalling of transcription or direct protein-protein interactions in transcription-coupled NER or global genome NER, respectively. Alkyltransferases have also been shown to interact with proteins involved in the initiation of DNA replication. Our single molecule imaging approaches using atomic force microscopy (AFM) and fluorescence optical tweezers, combined with on the one hand ensemble biophysical and functional biochemical assays and on the other hand crystallisation studies aim to provide mechanistic insight into the interactions between these fundamentally important DNA processing systems.