Regulation of mitotic chromosomes

有丝分裂染色体的调控

• 批准号: 10396982
• 负责人: Hironori Funabiki
• 金额: $ 83.06万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10396982
• 关键词: Affect; Antimitotic Agents; Binding Proteins; Biochemistry; Cancer Etiology; Cell Aging; Cell Death; Cells; Centromere; Chemotherapy-Oncologic Procedure; Chromatin; Chromosome Segregation; Chromosomes; Clinical Treatment; Competitive Binding; Complex; Congenital Abnormality; DNA; Development; Event; Face; Failure; Genetic Transcription; Genomic DNA; HELLS gene; Histones; Human; Image; Immune; Immunity; Immunodeficiency and Cancer; Innate Immune System; Kinetochores; Lead; Mediating; Methods; Microtubules; Mitosis; Mitotic; Mitotic Chromosome; Mitotic Spindle Apparatus; Molecular; Morphology; Nucleosomes; Organism; Paclitaxel; Regulation; Repetitive Sequence; Research; Role; Satellite DNA; Structure; Syndrome; Testing; Transcriptional Regulation; Xenopus; cancer cell; cell growth; chromatin protein; cytotoxic; developmental disease; egg; novel; preservation; programs; segregation; sensor; tumor

Project Summary Proper chromosome segregation during mitosis is fundamental to cell growth and organism development. Failures in this step lead to developmental diseases, immunodeficiency, and cancers. My research program aims to reveal molecular mechanisms critical for chromosome segregation and elucidate the consequences of their failures, which can be exploited to enhance the efficacy of chemotherapeutic treatments. 1) Roles of nucleosome regulators in chromosome segregation: During mitosis, chromosomes dramatically change their functions and morphology to support their segregation. Chromosomes become condensed, while promoting formation of mitotic apparatuses, such as kinetochores and spindle microtubules. Although histones are the most abundant chromatin proteins, the importance of histones in transcriptional regulation makes it challenging to dissect their direct roles in mitosis. Our lab has established a novel method to manipulate histones and evaluate their consequences using Xenopus egg extracts, which recapitulates a variety of chromatin events independently of transcription. We discovered that the chromosomal passenger complex (CPC) must interact with both nucleosomes and microtubules to support spindle assembly. As chromatin proteins regulated by the CPC, we discovered a novel nucleosome-remodeling complex composed of HELLS and CDCA7, relevant to Centromere instability and Facial anomalies (ICF) syndrome. By dissecting the roles of HELLS-CDCA7 and other nucleosome regulators, we will investigate the poorly understood mechanisms and functional significance of mitosis-specific control of nucleosome dynamics and functions. 2) Mechanisms that maintain human centromere integrity: Human centromeres, where kinetochores assemble to capture microtubules, are composed of a long array of repetitive element, α-satellite DNA. We have shown that α-satellite repetitive arrangement becomes unstable in cancer cells and during cellular senescence, and that centromere-binding proteins are important for preserving this arrangement. We will dissect mechanisms that maintain integrity of centromere-associated repetitive elements. 3) Recognition of mitotic failures by the innate immune system: We hypothesize that nucleosomes act as a hallmark that distinguish between genomic DNAs and foreign or aberrant DNAs. Consistent with this idea, we demonstrated that the nucleosome competitively binds and inhibits DNA-induced stimulation of the cytoplasmic DNA sensor, cGAS, a component of the innate immune system. We showed that during extended mitosis, cGAS is slowly activated and induce cell death. Cells that do not express cGAS are less prone to die during mitotic arrest induced by taxol, which is frequently used in cancer chemotherapy. Thus, cGAS expression level could be a predictor of the efficacy of taxol, and cGAS mediated-immunity may affect cytotoxic effect of taxol on tumors. We will investigate mechanisms behind cGAS-induced cell death and its relevance to clinical treatment with taxol.

项目摘要 有丝分裂期间的适当染色体分离是细胞生长和生物发育的基础。 此步骤中的失败导致发育疾病，免疫缺陷和癌症。我的研究计划 旨在揭示对染色体分离至关重要的分子机制并阐明 它们的失败，可以探索以提高化学治疗的效率。 1）核小体调节剂在染色体分离中的作用：在有丝分裂期间，染色体显着 改变其功能和形态以支持其隔离。染色体变得浓缩，而 促进有丝分裂设备的形成，例如动力学和纺锤微管。虽然组蛋白 是最丰富的染色质蛋白，组蛋白在转录调节中的重要性使得 具有挑战性的剖析其在有丝分裂中的直接作用。我们的实验室已经建立了一种新颖的方法来操纵 用爪蟾鸡蛋提取物评估并评估其后果，该提取物概括了多种 染色质事件独立于转录。我们发现染色体乘客综合体 （CPC）必须与核小组和微管相互作用，以支持纺锤体组件。作为染色质 由CPC调节的蛋白质，我们发现了一种由地狱组成的新型核小体复合体 和CDCA7，与丝粒不稳定和面部异常（ICF）综合征有关。通过解剖角色 地狱-CDCA7和其他核小体调节剂，我们将研究知识较低的机制 有丝分裂特异性控制核素动力学和功能的功能意义。 2）维持人体丝粒完整性的机制：人类centromeres，动物学组合 为了捕获微管，由一系列重复的元素α-卫星DNA组成。我们已经显示了 在癌细胞和细胞感应期间，α-卫星的重复布置变得不稳定，以及 该中心结合蛋白对于保留这种布置很重要。我们将剖析机制 维持着丝粒相关的重复元素的完整性。 3）先天免疫系统识别有丝分裂失败：我们假设核小体充当 区分基因组DNA和外国或异常DNA的标志。与这个想法一致，我们 证明核小体竞争性结合并抑制DNA诱导的细胞质刺激 DNA传感器，CGA，是先天免疫系统的组成部分。我们表明，在延长有丝分裂期间， CGA被缓慢地激活并诱导细胞死亡。不表达CGA的细胞在期间不太容易死亡 紫杉醇诱导的有丝分裂停滞，经常用于癌症化学疗法。那，CGAS表达水平 可以预测紫杉醇的有效性，而CGAS介导的免疫力可能会影响紫杉醇的细胞毒性作用 在肿瘤上。我们将研究CGAS引起的细胞死亡背后的机制及其与临床的相关性 用紫杉醇治疗。