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修饰是通过许多DNA修复机制来修复的，这些机制是针对特定的目标病变进行微调的。最近的一些研究也指出了不同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）系统蛋白的相互作用。烷基转移酶和糖基化酶可以分别通过停止转录或转录偶联NER或全球基因组NER中的直接蛋白-蛋白相互作用来启动NER。烷基转移酶也被证明与参与DNA复制起始的蛋白质相互作用。我们的单分子成像方法使用原子力显微镜（AFM）和荧光光学镊子，一方面结合整体生物物理和功能生化分析，另一方面结合结晶研究，旨在为这些基本重要的DNA处理系统之间的相互作用提供机制见解。

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.