SUMO靶向泛素连接酶RNF4对NF-kB信号通路的调控及分子机制研究

NF-kB pathway is one of the key signaling pathways in cells, which involves in the regulation of multiple biological processes such as cell proliferation, apoptosis and inflammation. Dysregulation of the pathway has been verifed closely related to many diseases including tumors. The regulation mechanism of it has become a research hotspot in life sciences, with great scientific significance. In the previous study, our lab had discovered a novel negative regulator of the NF-kB signaling pathway (Nature Immunology, 2008). Recently, we found another new clue that the SUMO-targeted ubiquitin ligase RNF4 maybe acts as another key negative regulator of the NF-kB pathway. In this project, through the biological experiments such as co-immunoprecipitation and in vitro kinase assay, we will use RNF4 gene overexpression or knockdown stable cell lines to study how RNF4 or the RNF4 complex regulates the activation and function of the NF-kB pathway, in order to reveal the molecular mechanism of RNF4 regulating the NF-kB signaling pathway and its role in NF-kB-associated biological processes such as cell immunity and inflammation. The development of the project is expected to discover a novel regulator of the NF-kB pathway, which could broaden our view of its regulation network.

NF-kB通路是细胞内的关键信号通路之一，参与调控细胞增殖、凋亡以及炎症等多种生物学效应。该通路的异常已证明与包括肿瘤在内的多种疾病密切相关，对其调控机制的研究已成为当前生命科学领域的热点，具有重要的科学意义。本实验室在前期研究中曾发现一个新的NF-kB通路的负调控子（Nature Immunology, 2008），近期我们对该通路的深入研究又获得了新线索，发现SUMO靶向泛素连接酶RNF4可能是NF-kB通路的另一个重要的负调控分子。本项目将利用已建立的稳定表达RNF4及其基因沉默的细胞模型，通过免疫共沉淀、体外激酶实验等生物学手段，深入阐明RNF4或RNF4蛋白复合体对NF-kB通路活性和功能的调节作用，揭示RNF4调控NF-kB通路的分子机制及在NF-kB参与的细胞免疫和炎性疾病中发挥的作用。本项目的实施有望发现一个新的NF-kB信号通路的调控子，拓展我们对其调控网络的全面认识。

NF-kB通路是细胞内的关键信号通路之一，该通路的异常与包括肿瘤在内的多种疾病密切相关，对其调控机制的研究具有重要的科学意义。我们通过筛选发现 SUMO 靶向泛素连接酶 RNF4 可能是 NF-kB 通路的另一个重要的负调控分子。本项目利用稳定表达 RNF4 及其基因沉默的细胞模型，通过转录活性测定、生物质谱分析、免疫共沉淀等生物学手段，明确了 RNF4对 NF-kB 通路活性和功能的调节作用，揭示了RNF4 调控 NF-kB 通路的分子机制。除此之外，我们还发现了NF-kB 信号通路中RNF4的重要新底物NKAP，并进一步阐明了NKAP的SUMO化修饰对细胞有丝分裂的重要调控作用。通过本项目的实施，我们发现了一个新的 NF-kB 信号通路的负调控子及其作用底物，拓展了我们对其调控网络的全面认识，为治疗肿瘤等相关疾病的治疗提供了潜在的新靶点。