Mitotic functions of MTUS1-defined Microtubule bundles

MTUS1 定义的微管束的有丝分裂功能

• 批准号: 329979611
• 负责人: Professor Dr. Oliver Gruß
• 金额: --
• 依托单位: Abteilung Zellteilung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/329979611?language=en
• 关键词: Mitotic; functions; MTUS1; defined; Microtubule

Microtubule associated proteins (MAPs) govern the function of microtubules (MT) in interphase and in mitosis. In previous approaches, we had identified a novel MT-associated protein complex that regulates the reorganisation of MT upon entry into mitosis in blastomeres during early development and in somatic cells. Recently, we discovered a novel component of this complex, Microtubule-associated tumor suppressor 1, MTUS1. Our preliminary data show that MTUS1 displays a unique MT binding and bundling pattern crosslinking two MT polymers in a stereotypic manner side by side. Modulating this bundling activity is ideally suited to regulate MT at the entry and during mitosis. We suggest a project to analyse the molecular mode of action of MTUS1 in mitosis. Our model of MTUS1 action includes several key points that can be experimentally tested, first and foremost a regulated protein conformation switch that enables or, vice versa, abolishes MTUS1 dimerization as the basis of its MT bundling activity. Dimerization of an “open” conformation generates a divalent MT binding unit consistent with MT tandem formation. We will test if the switch to dimeric MTUS1 and back, and thus MT tandem formation, may be guided by Rho family members and an abundant phosphorylation site in the C-terminus. We propose a project to analyse MTUS1 function, alone and in cooperation with its homologue MTUS2, as a paradigm of the action of MAPs in cell division. We aim at understanding how MTUS1 activity in bundling of MT tandems functions before, during and after mitosis in different experimental set-ups. Specific mutant variants (dimerization defective, Rho binding defective, MT binding defective, phosphorylation deficient) will be analysed consistently in vitro (i.e. using purified proteins), “ex vivo” (i.e. in Xenopus cell free extracts) and in vivo (i.e. in intact cells).

微管相关蛋白（MAPs）在细胞分裂间期和有丝分裂中控制微管的功能。在以前的方法中，我们已经确定了一种新的MT相关蛋白复合物，该复合物在早期发育和体细胞中进入有丝分裂后调节MT的重组。最近，我们发现了这种复合物的一种新成分，微管相关肿瘤抑制因子1，MTUS 1。我们的初步数据表明，MTUS 1显示出独特的MT结合和捆绑模式交联两个MT聚合物在一个刻板的方式并排。调节这种捆绑活动非常适合于在进入和有丝分裂期间调节MT。我们建议一个项目来分析MTUS 1在有丝分裂中的分子作用模式。我们的MTUS 1作用模型包括几个可以通过实验测试的关键点，首先是一个受调节的蛋白质构象转换，它可以使MTUS 1二聚化成为其MT捆绑活性的基础，反之亦然。“开放”构象的二聚化产生与MT串联形成一致的二价MT结合单元。我们将测试，如果开关到二聚MTUS 1和背部，因此MT串联形成，可以引导Rho家族成员和丰富的磷酸化位点的C-末端。我们提出了一个项目来分析MTUS 1的功能，单独和与其同源MTUS 2合作，作为一个范例的行动地图在细胞分裂。我们的目的是了解如何MTUS 1活动捆绑MT串联功能之前，期间和之后的有丝分裂在不同的实验设置。将在体外（即使用纯化蛋白）、“离体”（即在非洲爪蟾无细胞提取物中）和体内（即在完整细胞中）一致地分析特定突变变体（二聚化缺陷、Rho结合缺陷、MT结合缺陷、磷酸化缺陷）。