DNA携带着合成蛋白质和RNA所必须的遗传信息,它不断受到各种外源性和内源性DNA损伤因素的攻击。在细胞内存在的多种类型的DNA损伤中,最危险的是DNA双链断裂（DSBs）。DNA双链断裂在人们的日常生活中并不少见,引起DNA双链断裂的外源性因素包括电离辐射,化学治疗等；内源性因素包括DNA复制压力,氧化应激等。DNA双链断裂可以造成DNA突变、染色体易位、基因组不稳定、肿瘤发生、细胞衰老和死亡,进而导致癌症、先天性疾病和衰老。因此,细胞快速检测出自身的DNA双链断裂并进行有效修复对于细胞的生存是至关重要的。

现在已有研究证明，ZNF830能够直接与CtIP相互作用并促进CtIP被招募到DSB位点，从而加速同源重组修复（HR）过程中的末端切除。ZNF830通过调节HR介导的DNA修复，促进DNA损伤后的细胞存活，并加强癌细胞对化疗和放射治疗引起的DNA损伤的抵抗，可能为癌症的治疗药物提供新的靶点。然而ZNF830至今未有蛋白质结构的解析，因此，本课题组对ZNF830的结构及其对人体的生理意义产生了浓厚兴趣。

ZNF830也被称为Ccdc16，鼠源基因名称为Omcg1，它已被证明是一种参与前mRNA剪接的核锌指蛋白，在N末端含有一个锌脂（ZnF）结构域，在C末端含有一个coiled-coil结构域，对于维持基因组的稳定性至关重要。本文中，我们对ZNF830结构的解析可以为DNA修复中的同源重组研究提供重要的信息，有助于我们从分子层面研究其生物功能，为癌症治疗提供新的思考方向。在ZNF830相互作用蛋白的探究实验中，首先通过GST-Pulldown实验检验出与ZNF830有相互作用的蛋白PPIL2，并检验出ZNF830的C端和PPIL2的C端有相互作用。接着通过微量热泳动（MST）实验得到ZNF830和PPIL2的结合常数，表明两者有很强的结合作用。最后利用Alphafold软件模拟出ZNF830-PPIL2复合物的晶体结构，并通过GST-pulldown实验检验出ZNF830和PPIL2的相互作用位点。

泛素化是指泛素在特殊的酶作用下，将细胞内的蛋白质分类，从中选出靶蛋白分子，并对靶蛋白进行特异性修饰的过程，通过泛素化途径可以控制多种细胞进程。PPIL2一种具有 U-box 结构域的 E3 泛素连接酶，我们通过实验发现ZNF830是PPIL2的一个泛素化底物，并检验出PPIL2泛素化ZNF830的泛素化位点以及泛素化类型。综上所述，本论文为ZNF830结构的研究奠定了基础，探究出人体内ZNF830相互作用的蛋白，揭示ZNF830在人体内的生理意义，对未来新的作用靶点鉴定以及抗癌药物的开发具有一定的帮助。

DNA, which carries the genetic information necessary for the synthesis of proteins and RNA, is constantly attacked by a variety of exogenous and endogenous DNA damage factors. Of the many types of DNA damage that exist inside cells, the most dangerous is DNA double strand breaks (DSBs). DNA double strand breaks are not rare in People's Daily life. The exogenous factors that cause DNA double strand breaks include ionizing radiation, chemotherapy and so on. Endogenous factors include DNA replication pressure, oxidative stress and so on. DNA double strand breaks can cause DNA mutation, chromosomal translocation, genomic instability, tumorigenesis, cell senescence and death, leading to cancer, congenital diseases and senescence. Therefore, it is essential for cells to quickly detect their own DNA double-strand breaks and effectively repair them for cell survival.

ZNF830 has been shown to interact directly with CtIP and facilitate CtIP recruitment to DSB sites, thus accelerating terminal resection during homologous recombination repair (HR). By regulating HR-mediated DNA repair, ZNF830 promotes cell survival after DNA damage and strengthens cancer cells' resistance to DNA damage caused by chemotherapy and radiation therapy, potentially providing new targets for therapeutic drugs in cancer. However, the protein structure of ZNF830 has not been analyzed so far, so this research group has a strong interest in the structure of ZNF830 and its physiological significance to human body.

ZNF830, also known as Ccdc16 and derived from the mouse gene Omcg1, has been shown to be a nuclear zinc finger protein involved in pre-mrna splicing, containing a zinc lipid (ZnF) domain at the N-terminal and a coiled coil domain at the C-terminal that is critical for maintaining genomic stability. In this paper, our analysis of the structure of ZNF830 can provide important information for the study of homologous recombination in DNA repair, help us to study its biological function from the molecular level, and provide a new direction for cancer treatment. In the experiment to explore the interacting protein of ZNF830, the protein PPIL2 interacting with ZNF830 was first detected through GST-Pulldown experiment, and the interaction between the C terminus of ZNF830 and the C terminus of PPIL2 was detected. Then, the binding constants of ZNF830 and PPIL2 were obtained by microthermometry (MST) experiments, which showed that the two had strong binding effect. Finally, Alphafold software was used to simulate the crystal structure of ZNF830-PPIL2 complex, and the interaction site between ZNF830 and PPIL2 was tested by GST-pulldown experiment.

Ubiquitination refers to the process that ubiquitin classifies proteins in cells under the action of special enzymes, selects target protein molecules from them, and makes specific modifications to target proteins. A variety of cellular processes can be controlled through ubiquitination. PPIL2 is an E3 ubiquitin ligase with U-box domain. Through experiments, we found that ZNF830 is a ubiquitin substrate of PPIL2, and tested the ubiquitin site and type of ubiquitin of PPIL2. In summary, this paper lays a foundation for the study of the structure of ZNF830, explores the proteins that interact with ZNF830 in human body, reveals the physiological significance of ZNF830 in human body, and has certain help for the identification of new action targets and the development of anticancer drugs in the future.