Dissecting the role of Aurora A kinase in patterning the cell cortex during cytokinesis.

项目摘要/摘要 胞质分裂是有丝分裂的最后一步，有助于一个细胞分裂成两个细胞。 子代细胞。动物细胞通过皮质肌动球蛋白的收缩实现胞质分裂 在分离的染色体之间围绕细胞赤道形成的收缩环。故障： 胞质分裂可导致四倍体细胞的形成，而四倍体细胞被认为是一种重要的中间体 在肿瘤发生方面。为了确保遗传物质的均匀分配，收缩环组件 由后期纺锤体控制。后期主轴发送两个叠加信号， 上皮层的收缩能力；来自中央纺锤体的信号，形成于 分离染色体会促进赤道皮质的收缩能力，而来自 中心体微管抑制非赤道皮质的收缩。最近的工作在 我的赞助实验室中的线虫已经牵涉到有丝分裂激酶极光A在抑制 收缩环蛋白在非赤道皮质上的积聚。然而，这一功能是否 Aurora A的基因在人类细胞中是保守的，而Aurora A的身份是介导靶点 对皮质收缩的抑制作用目前尚不清楚。在拟议的工作中，我将确定 在人类细胞中，Aurora A在模式皮层收缩中的作用是否保守，使用 利用线虫分子置换技术识别极光A介导的靶标 抑制皮质收缩能力，并确定Aurora A抑制收缩能力的程度 结合中心心轴促进收缩，形成收缩环。在Aim1，我 将开发一种检测方法来监测非赤道皮质在 并用它来确定极光A在这一过程中是否具有保守的作用 Aurora A在质膜上的异位靶向是否会抑制收缩。在目标2a中， 我将利用线虫胚胎为分子替代实验提供的优势 对胞质分裂调节因子进行无偏筛选以确定介导Aurora A的靶点 中心体酯类抑制皮质收缩的能力，并将测试已识别的调节部位 在人类细胞中进行保护。在目标2B中，我将确定Aurora A和中心纺锤体是如何派生的 信号被集成，以实现收缩环位置和尺寸的精确规范。 总而言之，这项工作将提供对极光A如何促进大脑皮层模式形成的关键洞察 细胞分裂时的收缩能力。靶向Aurora A的AS抑制剂目前正在进行临床试验，可能是 化疗药物，了解Aurora A在调节收缩能力中的作用是如何相关的 它在肿瘤发生中的作用有可能影响癌症的治疗策略。

PROJECT SUMMARY/ABSTRACT Cytokinesis is the final step in mitosis and facilitates the physical cleavage of one cell into two daughter cells. Animal cells achieve cytokinesis through the constriction of a cortical actomyosin contractile ring that forms around the cell equator between the segregating chromosomes. Failure of cytokinesis can lead to the formation of tetraploid cells that are thought to be an important intermediate in tumorigenesis. To ensure equal partitioning of the genetic material, contractile ring assembly is controlled by the anaphase spindle. The anaphase spindle sends two superimposed signals that pattern the contractility of the overlying cortex; a signal from the central spindle that forms between the separating chromosomes promotes contractility of the equatorial cortex, and a signal from the centrosomal microtubule asters suppresses contractility of the non-equatorial cortex. Recent work in C. elegans in my sponsor lab has implicated the mitotic kinase Aurora A in suppressing the accumulation of contractile ring proteins on the non-equatorial cortex. However, whether this function of Aurora A is conserved in human cells and the identity of the Aurora A target sites that mediate suppression of cortical contractility are currently unknown. In the proposed work, I will determine whether the role of Aurora A in patterning cortical contractility is conserved in human cells, use molecular replacement techniques in C. elegans to identify the targets of Aurora A-mediated suppression of cortical contractility, and determine how Aurora A suppression of contractility is integrated with central spindle promotion of contractility to pattern contractile ring formation. In Aim1, I will develop an assay to monitor the suppression of contractility on the non-equatorial cortex during cytokinesis in human cells and use it to determine if Aurora A has a conserved role in this process and whether ectopic targeting of Aurora A to the plasma membrane can suppress contractility. In Aim 2A, I will capitalize on the advantages the C. elegans embryo offers for molecular replacement experiments to perform an unbiased screen of cytokinesis regulators to identify the Aurora A target sites that mediate the ability of centrosomal asters to suppress cortical contractility and will test identified regulatory sites in human cells for conservation. In Aim 2B I will determine how Aurora A and central spindle-derived signals are integrated to allow for the precise specification of contractile ring location and dimensions. Collectively, this work will provide crucial insight into how Aurora A contributes to patterning cortical contractility in dividing cells. As inhibitors targeting Aurora A are currently in clinical trials as potential chemotherapeutic agents, understanding how the role of Aurora A in regulating contractility is related to its functions in tumorigenesis has the potential to impact therapeutic strategies in cancer.