电荷转移介导的线粒体DNA复制机制研究

Reactive oxygen species (ROS) interact with DNA essentially via the transfer of uncoupled free electrons. This process has been poorly studied due to the limit of related technique. Recent studies find that DNA double strands could act like "wires" to allow charge transport within the double strands. These findings indicate that free electrons could act like electrical signal to mediated biological function. Our previous researches find that ionizing radiation-induced ROS could affect mitochondrial DNA (mtDNA) conformations and damage, and these two are closely related to mtDNA replication.We therefore try to investigate the potential effects of charge transport on mtDNA replication during the initial interaction between ROS and DNA. We will use Femtosecond pump-probe technique to detect charge transport events during ROS and DNA interaction; Surface plasmon resonance technique will be employed to study the interaction of mtDNA replication related protein HNth1 and mtDNA. Mitochondrial mass, mtDNA copy number and consequential cell fate will also be detected after ROS stimulation. We hope we could elucidate the potential mechanism of charge transport-mediated mtDNA replicaiton by the combination of physical chemistry and biological methods.

活性氧与DNA的相互作用本质上是未配对自由电子的转移过程，这一过程的研究在此之前一直由于技术的限制未能得到广泛开展。最新研究发现DNA双链具有类似导体的性质，电荷可以在DNA双链内部快速传输，这说明自由电子可能作为一种“电信号”介导生物学功能。我们的初步研究表明电离辐射产生的活性氧对线粒体DNA构象及损伤都有影响，而这两者都与线粒体DNA复制密切相关。为此，我们尝试从活性氧与DNA的原初反应阶段探索电荷转移在引起线粒体DNA复制中所起的作用。研究将采用飞秒泵浦技术在飞秒尺度实时检测活性氧与DNA双链间的电荷转移现象，使用光学表面等离子共振技术确定线粒体DNA复制相关蛋白HNth1与线粒体DNA的相互作用。同时还将检测活性氧刺激后线粒体DNA拷贝、线粒体数量及相关细胞命运等。我们希望通过结合物理化学和生物的研究手段探讨电荷转移在诱导线粒体DNA复制上的作用机理。

活性氧与DNA的相互作用本质上是未配对自由电子的转移过程，这一过程的研究在此之前一直由于技术的限制未能得到广泛开展。最新研究发现DNA双链具有类似导体的性质，电荷可以在DNA双链内部快速传输，这说明自由电子可能作为一种“电信号”介导生物学功能。我们的初步研究表明电离辐射产生的活性氧对线粒体DNA构象及损伤都有影响，而这两者都与线粒体DNA复制密切相关。为此，我们尝试从活性氧与DNA的原初反应阶段探索电荷转移在引起线粒体DNA复制中所起的作用。我们采用飞秒泵浦技术在飞秒尺度实时检测活性氧与DNA双链间的电荷转移现象，并系统确定线粒体DNA复制相关蛋白HNth1与线粒体DNA的相互作用。同时发现适量活性氧刺激后线粒体DNA拷贝、线粒体数量都呈现上升趋势。进一步的研究表明活性氧刺激能够通过显著增加线粒体DNA控制区序列的合成来调节线粒体DNA拷贝数量。综上所述，我们结合物理化学和生物的研究手段探讨了电荷转移在诱导线粒体DNA复制上的作用机理。