Chromosome dynamics and organizations necessary for faithful chromosome segregation

忠实染色体分离所需的染色体动力学和组织

• 批准号: 10797444
• 负责人: Aussie Suzuki
• 金额: $ 23.5万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2027-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10797444
• 关键词: 3-Dimensional; Aneuploidy; Binding; Calibration; Cell Nucleus; Cell division; Cells; Chromatin; Chromosomal Instability; Chromosome Positioning; Chromosome Segregation; Chromosome Structures; Chromosome Territory; Chromosomes; Computer software; Coupled; Defect; Detection; Ensure; Evolution; Frequencies; Gene Expression Regulation; Genomics; Goals; Individual; Interphase; Kinetochores; Maintenance; Malignant Neoplasms; Mammalian Cell; Mediating; Methods; Microtubules; Mitosis; Mitotic; Mitotic Chromosome; Molecular; Needles; Pathway interactions; Patient-Focused Outcomes; Phosphorylation; Phosphotransferases; Positioning Attribute; Process; Proteins; Public Health; Quantitative Microscopy; Regulation; Testing; Therapeutic; Tumor Promotion; Work; aurora B kinase; chromosome loss; chromosome replication; daughter cell; developmental disease; imaging modality; improved; innovation; insight; protein structure; segregation; spatiotemporal; superresolution microscopy

PROJECT SUMMARY Cell division is a conserved process by which replicated chromosomes are equally partitioned into two daughter cells. Errors in this process often result in gains or losses of chromosomes, known as aneuploidy, which can cause and promote tumors and developmental diseases. During mitotic progression, chromosomes dynamically change their positions in a force-dependent manner via forces generated at kinetochores, macro-molecular protein structures built on centromeric chromatin that serves as platforms for microtubule assembly. While chromosome territories, regions preferentially occupied by specific chromosomes in interphase nuclei, have been established and are known to be involved in gene regulation and genomic protection, the presence and function of chromosome organization in mitosis have not been adequately explored. Our long-term goals are to characterize “mitotic chromosome territories” in mammalian cells and to uncover the function behind spatiotemporal regulation of both chromosome organization and kinetochore dynamics in ensuring faithful chromosome segregation. In this proposal, we will test the hypothesis that there exist chromosome organizations in mitosis as in interphase nuclei using a super-resolution microscopy method we recently developed, which will allow us to identify full sets of individual chromosomes and determine their spatial organization in mammalian cells. If there exist mitotic chromosome territories, we will explore how and when they are established and their evolution throughout mitosis. We also hypothesize that major mitotic defects (unaligned chromosomes, lagging chromosomes, and chromosome bridges) are associated with improper chromosome organization. We will examine this hypothesis by identifying which chromosomes are involved in each defect with increased frequency and determine their positionings. Mitotic cells have two major pathways for correcting mitotic errors, mediated by Aurora A or Aurora B kinases. Both kinases are spatially regulated and phosphorylate a highly conserved microtubule-binding kinetochore protein, Ndc80/Hec1, to destabilize improper microtubule bindings for promotion of error correction and regulation of SAC (spindle assembly checkpoint) activity. Aurora A-mediated error corrections require proximity of erroneous chromosomes to the spindle poles, where Aurora A is concentrated. On the other hand, Aurora B-mediated error corrections depend on dynamic deformations of kinetochores. These suggest that mitotic chromosome positioning, coupled with kinetochore dynamics, orchestrate the cooperation between Aurora A and Aurora B-mediated error correction machineries. We will dissect the contributions of chromosome positioning and kinetochore dynamics towards Aurora A and Aurora B error corrections using force-calibrated microneedles and a semi-automated, quantitative microscopy analysis software that we recently developed called the 3D speckle analyzer (3D-Speckler). Our proposed work will provide new, mechanistic insights into mitotic chromosome organization and its contribution toward ensuring the integrity of chromosome segregation, which will contribute towards developing better therapeutic and detection strategies for cancer and developmental diseases for improved patient outcomes.

项目概要 细胞分裂是一个保守的过程，通过该过程，复制的染色体被平均分配成两个子代 这个过程中的错误通常会导致染色体的增加或丢失，称为非整倍体。 在有丝分裂过程中，染色体动态地引起和促进肿瘤和发育疾病。 通过动粒、大分子产生的力以力依赖的方式改变它们的位置 建立在着丝粒染色质上的蛋白质结构，作为微管组装的平台。 染色体区域，即间期核中特定染色体优先占据的区域， 已经确定并已知参与基因调控和基因组保护，存在和 染色体组织在有丝分裂中的功能尚未得到充分探索。 表征哺乳动物细胞中的“有丝分裂染色体区域”并揭示其背后的功能 染色体组织和着丝粒动力学的时空调节以确保忠实 在本提案中，我们将检验存在染色体组织的假设。 使用我们最近开发的超分辨率显微镜方法，在有丝分裂和间期细胞核中进行研究，这将 使我们能够识别哺乳动物的全套个体染色体并确定它们的空间组织 如果细胞存在有丝分裂染色体区域，我们将探讨它们是如何、何时建立的以及它们的作用。 在整个进化过程中，我们还追踪了主要的有丝分裂缺陷（染色体未对齐、滞后）。 染色体和染色体桥）与不正确的染色体组织有关。 通过识别哪些染色体参与频率增加的每个缺陷来检验这一假设 并确定它们的定位 有丝分裂细胞有两个主要途径来纠正有丝分裂错误，介导。 通过 Aurora A 或 Aurora B 激酶，这两种激酶均受到空间调节并磷酸化高度保守的蛋白。 微管结合动粒蛋白 Ndc80/Hec1，以破坏不正确的微管结合 极光A介导 纠错需要错误染色体接近纺锤体极点，其中 Aurora A 是 另一方面，Aurora B 介导的误差修正取决于 的动态变形。 这些表明有丝分裂染色体定位与动粒动力学相结合， 我们将协调 Aurora A 和 Aurora B 介导的纠错机制之间的合作。 剖析染色体定位和动粒动力学对 Aurora A 和 Aurora B 的贡献 使用力校准微针和半自动定量显微镜分析进行误差校正 我们最近开发的软件称为 3D 散斑分析仪 (3D-Speckler)。 为有丝分裂染色体组织及其对确保有丝分裂染色体的贡献提供新的、机械的见解 染色体分离的完整性，这将有助于开发更好的治疗和检测 癌症和发育性疾病的策略，以改善患者的治疗结果。

项目成果

Extended regulation interface coupled to the allosteric network and disease mutations in the PP2A-B56δ holoenzyme.

扩展的调节接口耦合到 PP2A-B56δ 全酶的变构网络和疾病突变。

• DOI: 10.1101/2023.03.09.530109
• 发表时间: 2023
• 期刊: bioRxiv : the preprint server for biology
• 作者: Wu,Cheng-Guo;Balakrishnan,VijayaK;Parihar,PankajS;Konovolov,Kirill;Chen,Yu-Chia;Merrill,RonaldA;Wei,Hui;Carragher,Bridget;Sundaresan,Ramya;Cui,Qiang;Wadzinski,BrianE;Swingle,MarkR;Musiyenko,Alla;Honkanen,Richard;Chung,Wen
• 通讯作者: Chung,Wen

Semi-automated 3D fluorescence speckle analyzer (3D-Speckler) for microscope calibration and nanoscale measurement.

• DOI: 10.1083/jcb.202202078
• 发表时间: 2023-04-03
• 期刊: The Journal of cell biology