MERIT40-Tankyrase1相互作用对纺锤体组装影响的研究

发布时间：2018-05-02 15:45

本文选题：纺锤体组装 + 泛素化　；参考：《深圳大学》2017年硕士论文

【摘要】：高等真核细胞通过有丝分裂复制后的两条染色体通过染色体分离的方式精确分配到两个子代细胞中,对维持基因组稳定性起着常重要的作用。有丝分裂依赖于微管为基础的双极纺锤体的组装和功能。细胞内多种蛋白翻译后修饰参与了这个过程的严密调控,包括磷酸化、泛素化和ADP核糖基化等。其中,泛素化是最为重要的一种蛋白质翻译后修饰,可调控蛋白质分子的定位、转运和相互作用,参与包括有丝分裂在内的诸多生物学过程。与其它翻译后修饰一样,泛素化是一个动态可逆的过程,泛素分子或泛素链可以被去泛素化酶水解,从而调控蛋白分子的泛素化水平和功能。BRISC是一个K63连接特异的去泛素化酶,由MERIT40、BRCC36、BRCC45和ABRO1组成,参与细胞内多个生物过程,如抗病毒免疫调控、炎性反应和纺锤体组装等。但它在纺锤体组装中的作用和机制还不是十分清楚。我们通过免疫荧光、免疫共沉淀、Pull Down、western blot等实验研究发现:(1)Tankyrase 1与MERIT40、BRCC36相互作用并定位于纺锤极;(2)RXXPEG是MERIT40纺锤极定位、MERIT40与Tankyrase 1相互作用必需的;(3)Tankyrase 1的亚结构域ARC V在Tankyrase 1与MERIT40-BRCC36相互作用中起主要作用;(4)MERIT40的RXXPEG突变体R28A呈现有丝分裂表型缺陷(5)Tankyrase 1在有丝分裂期可以被K63连接泛素化修饰,其修饰水平受MERIT40去泛素化酶复合物负性调控。RXXPEG突变削弱或破坏MERIT40与Tankyrase 1的相互作用,引起Tankyrase 1的K63连接泛素化水平显著增高,这可能进一步导致其PAR修饰酶活性失调,最终影响细胞纺锤体组装功能。
[Abstract]:The higher eukaryotic cells are divided into two progenies precisely by chromosome separation after mitotic replication, which plays an important role in maintaining genomic stability. Mitosis depends on the assembly and function of microtubulo-based bipolar spindles. Many protein posttranslational modifications are involved in this process, including phosphorylation, ubiquitin and ADP ribonucleylation. Ubiquitin is the most important post-translational modification of proteins, which regulates the localization, transport and interaction of protein molecules, and participates in many biological processes, including mitosis. Like other post-translational modifications, ubiquification is a dynamic reversible process in which the ubiquitin molecule or the ubiquitin chain can be hydrolyzed by diubiquitin, thereby regulating the level and function of ubiquitization of protein molecules. BRISC is a K63 linked specific diubiquitin enzyme. MERIT40 BRCC36 BRCC45 and ABRO1 are involved in many biological processes, such as anti-viral immune regulation, inflammatory response and spindle assembly. However, its role and mechanism in spindle assembly is not very clear. We use immunofluorescence, The results of immunoprecipitation with pull blot and other experimental studies have found that the interaction of 1 / 1 / 1 Tankyrase 1 with MERIT40 / BRCC36 / RXXPEG is the essential subdomain of the interaction between MERIT40 and Tankyrase 1. ARC V plays a major role in the interaction between Tankyrase 1 and MERIT40-BRCC36. The subdomain ARC V plays a major role in the interaction between MERIT40 and Tankyrase 1, and its subdomain ARC V plays a major role in the interaction between MERIT40 and ARC 1, which is the main subdomain of the interaction between MERIT40 and Tankyrase 1. The RXXPEG mutant R28A, which acts on MERIT40, showed mitotic phenotypic defects and Tankyrase 1 could be modified by K63 ligation ubiquification during mitosis. Its modification level was weakened or destroyed by the negative regulation of MERIT40 desuginase complex. RXXPEG mutation, which resulted in a significant increase in the K63 ligand ubiquitin level of Tankyrase 1, which may further lead to the imbalance of PAR modifying enzyme activity. Finally, the function of cell spindle assembly is affected.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q253

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