Microtubule dynamics and error correction

修改项目摘要/摘要部分 这个项目的主要目标是了解驱动蛋白相关的马达和动态微管如何产生力来控制染色体分离的保真度。微管和马达都是抗癌药物的理想靶点，但要为开发治疗药物做出明智的选择，有必要详细了解它们对细胞分裂的贡献。MCAK/Kif 2C是一种MT解聚驱动蛋白，其控制纺锤体内的MT长度并抑制染色体不稳定性（CIN）。使用CRISPR/Cas9工程细胞，雷帕霉素依赖性重新定位和长期实时成像，我们已经确定了这种蛋白质对增强染色体分离保真度的精确贡献，这将使我们能够理解为什么这种蛋白质在致瘤细胞中拯救CIN及其未来作为治疗靶点的潜力。MCAK/Kif 2C也与中心体密切相关，它有可能抑制MT生长并影响中心体分离。我们已经确定了另外两个研究较少的中心体相关驱动蛋白，Kif 25和Kif 9，它们分别在中心体凝聚和中心体卫星定位中起作用，并且也影响中心体分离和定位。改变中心体在细胞培养物中的定位对细胞活力的影响有限。然而，Kif 9和Kif 25都在脊椎动物中广泛表达。由于Kif 25，特别是，是最高表达的大脑，它提供了一个机会，研究中心体凝聚力的脊椎动物发育和神经干细胞分裂的作用，使用针对Kif 25引入早期斑马鱼胚胎的吗啉代。我们的目标是使用活细胞和固定细胞成像工具和转基因细胞系来精确地研究这些驱动蛋白对保持基因组保真度和长期细胞命运的贡献。最终，可以利用这一知识基础来开发针对驱动蛋白酶学或MT动力学的新疗法。

Modified Project Summary/Abstract Section The broad goal of this project is to understand how force generation by kinesin-related motors and dynamic microtubules controls the fidelity of chromosome segregation. Both microtubules and motors represent excellent targets for anti-cancer drugs but to make wise choices for developing therapeutics it is necessary to understand their contribution to cell division in detail. MCAK/Kif2C is a MT depolymerizing kinesin that controls MT length within the spindle and supresses chromosome instability (CIN). Using CRISPR/Cas9 engineered cells, rapamycin-dependent relocalization and long-term live imaging we have pinpointed the precise contribution that this protein makes to enhance the fidelity of chromosome segregation which will enable us to understand why this protein rescues CIN in tumorigenic cells and its future potential as a therapeutic target. MCAK/Kif2C is also strongly associated with centrosomes where it has the potential to suppress MT outgrowth and influence centrosome separation. We have identified two other poorly studied centrosome-associated kinesins, Kif25 and Kif9, that function in centrosome cohesion and centrosome satellite positioning respectively and that also impact centrosome separation and positioning. Altered centrosome positioning in cell culture has limited effects on cell viability. However, Both Kif9 and Kif25 are widely expressed in vertebrates. Because Kif25, in particular, is most highly expressed in brain it affords an opportunity to investigate the role of centrosome cohesion in vertebrate development and neural stem cell division using morpholinos directed against Kif25 introduced into early zebrafish embryos. We aim to use live and fixed-cell imaging tools and transgenic cell lines to investigate, with precision, the contribution that these kinesins make to preserving the fidelity of the genome and to long-term cell fate. Ultimately this knowledge base can be leveraged to develop new therapies that target kinesin enzymology or MT dynamics.