Roles of chromosomal factors in chromosome segregation

染色体因素在染色体分离中的作用

• 批准号: 6964186
• 负责人: Hironori Funabiki
• 金额: $ 32.11万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6964186
• 关键词: SDS polyacrylamide gel electrophoresis; Xenopus oocyte; binding proteins; cell cycle; chromosome movement; enzyme activity; mass spectrometry; microtubules; mitotic spindle apparatus; phosphotransferases; polymerase chain reaction; tubulin

DESCRIPTION (provided by applicant): Chromosomes must be equally segregated during cell division. Eukaryotes use microtubules to control the positioning and movement of chromosomes. In addition to kinetochores and centrosomes, the chromatin that makes up the chromosome arms plays important roles in organizing spindle microtubules. The long-term goal of this proposal is to understand how chromosomal factors influence the local environment and coordinate chromosome segregation. To approach this goal, we used expression screening to identify new metaphase chromosome-binding proteins, and discovered Dasra A and Dasra B, two new components of the vertebrate chromosomal passenger complex, which contains the kinase Aurora B. This complex plays roles in the spindle checkpoint and cytokinesis, and it has been proposed to regulate microtubule dynamics. Whereas Dasra B is conserved among vertebrates, Dasra A homologs can be found in fishes, frogs and chicken, but not in mammals. One of the characteristics distinguishing Dasra A-containing vertebrates from mammals is the rapid early embryonic cell divisions during which the checkpoint controls are suppressed, suggesting that Dasra A may be specialized to regulate spindle assembly in these rapid cell division cycles. Using Xenopus egg extracts, we propose to: 1) Determine the full constituents of the chromosomal passenger complex. 2) Distinguish the functions of Dasra A and Dasra B in chromatin-induced spindle assembly, in activation/maintenance of the spindle assembly checkpoint, and in the regulation of the kinase activity of Aurora B. 3) Examine how the chromosomal passenger complex is regulated on chromosomes. Do chromosomes biochemically activate the chromosomal passenger complex, or are chromosomes simply used for increasing local concentration of the complex? The findings of this proposal will help us understand how normal cells segregate their chromosomes accurately and how this process fails in cancer cells and in birth defects.

描述（由申请人提供）：在细胞分裂过程中必须平均隔离染色体。真核生物使用微管来控制染色体的定位和运动。除了动力学和中心体外，构成染色体臂的染色质在组织纺锤体微管中起着重要作用。该提案的长期目标是了解染色体因素如何影响局部环境并协调染色体隔离。为了实现这一目标，我们使用表达筛选来识别新的中期染色体结合蛋白，并发现了Dasra A和Dasra B，这是脊椎动物染色体乘客综合体的两个新组件，其中包含激酶Aurora B.这种复合物在跨跨度检查点和细胞动力学中起着作用，并在刺激性调节器中起作用。尽管Dasra B在脊椎动物中是保守的，但Dasra A在鱼类，青蛙和鸡肉中可以找到同源物，但在哺乳动物中找不到。区分含DASRA A的脊椎动物和哺乳动物的特征之一是抑制检查点对照的快速早期胚胎细胞分裂，这表明Dasra A可以专门用于调节这些快速细胞分裂周期中的纺锤体组件。使用爪蟾卵提取物，我们建议：1）确定染色体乘客复合物的完整成分。 2）区分DASRA A和DASRA B在染色质诱导的纺锤体组件中的功能，激活/维持主轴组件检查点，并在Aurora B的调节中调节Aurora B. 3）研究如何调节染色体乘客复合物在染色体上。染色体生化是否会激活染色体乘客复合物，还是仅仅用于增加络合物的局部浓度？该提案的发现将有助于我们了解正常细胞如何准确地分离其染色体以及该过程在癌细胞和先天缺陷中如何失败。