Molecular Analysis of Pericentric Sister Chromatid Cohesion

中心周围姐妹染色单体凝聚力的分子分析

• 批准号: 7780697
• 负责人: PAUL Connor MEGEE
• 金额: $ 30.18万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7780697
• 关键词: Address; Anaphase; Biochemical Genetics; Biological; Biological Models; Biology; Cell Cycle; Cell division; Cell physiology; Cells; Centromere; Chromatin; Chromatin Loop; Chromosome Arm; Chromosome Segregation; Chromosome Structures; Chromosomes; Complex; Congenital Disorders; DNA; DNA Double Strand Break; DNA Repair; DNA Repair Gene; DNA Replication Timing; DNA-Directed RNA Polymerase; Data; Deposition; Development; Dimensions; Distal; Dosage Compensation (Genetics); Down Syndrome; Elements; Epigenetic Process; Eukaryota; Event; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genomics; Goals; Growth; Hereditary Disease; Human; Intercistronic Region; Intergenic Sequence; Kinetochores; Lead; Location; Maintenance; Malignant Neoplasms; Mediating; Metabolism; Modeling; Molecular; Molecular Analysis; Morphogenesis; Nature; Nuclear; Pathway interactions; Play; Polymerase; Positioning Attribute; Process; Proteins; RNA Polymerase II; Recruitment Activity; Research; Role; Saccharomyces cerevisiae; Saccharomycetales; Shapes; Sister; Sister Chromatid; Spatial Distribution; Spontaneous abortion; Testing; Vertebrates; X Inactivation; Yeasts; arm; base; centromere protein A; centromere protein C; chromatin modification; cohesin; cohesion; daughter cell; design; insight; interest; mutant; novel; protein complex; public health relevance; research study; segregation; transcription termination; transmission process; tumorigenesis

DESCRIPTION (provided by applicant): Accurate chromosome segregation is essential for the successful transmission of genetic information to daughter cells, and deficiencies in this process are associated with miscarriages, congenital disorders, and tumorigenesis. Integral to proper chromosome segregation is the cohesion or physical association of replicated sister chromatids, which is mediated by the evolutionarily conserved cohesin complex. Cohesins are involved not only in chromosome segregation, but also play important roles in DNA repair and gene regulation. Cohesin's spatial distribution on budding yeast chromosomes is highly reproducible, suggesting that it plays important roles in chromosome structure and function. Cohesins are frequently found in intergenic regions between convergently transcribed genes, indicating interplay between cohesin distributions and transcription that is currently not characterized. Notably, extensive cohesin-enriched domains assemble in pericentromeric (kinetochore-flanking) regions, where they promote chromosome biorientation and resist precocious sister chromatid separation. We showed previously that budding yeast kinetochores direct pericentromeric cohesin domain assembly. Our preliminary data indicate that pericentromeric cohesin domains are assembled epigenetically by a nucleation and spreading mechanism. We test the veracity of this model in Specific Aim 1 by determining whether loop formation adjacent to the centromere impedes cohesin recruitment in distal sequences. Pericentromeric chromatin will also be isolated and its protein composition characterized in an unbiased screen for kinetochore-associated factors or epigenetic chromatin modifications that direct cohesin domain assembly. Lastly, insulators that limit cohesin recruitment will be used to delineate the minimally effective pericentromeric domain necessary for high fidelity chromosome transmission. Preliminary data also indicate that cohesin distributions are directed by the prior association of the Scc2/Scc4 cohesin loader with intergenic sequences. In the second aim, we endeavor to determine the mechanisms and significance of loader and cohesin localization on chromosome arms. The order and interdependence of association of the RSC ATP-dependent chromatin remodeler, Scc2/Scc4, and cohesin will be determined at chromosome arm cohesin-associated regions to dissect the pathway for cohesin deposition. The contribution of RNA polymerase II-dependent transcription in the establishment of cohesin loader distributions will be examined following polymerase inactivation and the mechanism and significance of cohesin redistribution in an RNA polymerase II transcription termination mutant are examined to delineate the nature of the relationship between transcription and cohesin localization. The role of budding yeast cohesins in the promotion of RNA polymerase II transcription termination will be determined using conditional cohesin mutants. PUBLIC HEALTH RELEVANCE: Chromosomes must be accurately duplicated and segregated to daughter cells during each cell division, and errors in these events can lead to cancer or genetic disease, such as Down syndrome. The accurate segregation of replicated chromosomes, or sister chromatids, to daughter cells requires that sisters physically associate with one another throughout much of the cell cycle. In this application, we endeavor to understand how the proteins that mediate the physical association of sister chromatids, called cohesins, are recruited to proper locations on the chromosome to mediate chromosome segregation, DNA repair, and gene regulation, each of which is important for the maintenance of genomic integrity.

描述（由申请人提供）：准确的染色体分离对于成功地传播遗传信息向子细胞是必不可少的，并且在此过程中的缺陷与流产，先天性疾病和肿瘤发生有关。适当的染色体分离的积分是复制的姐妹染色单体的内聚力或物理缔合，该染色质剂是由进化保守的粘蛋白复合物介导的。粘着素不仅参与染色体分离，而且在DNA修复和基因调节中起重要作用。凝聚蛋白在发芽的酵母染色体上的空间分布非常可重现，这表明它在染色体的结构和功能中起着重要作用。粘着素经常在趋同转录基因之间的基因间区域中发现，这表明粘着蛋白分布与当前未表征的转录之间的相互作用。值得注意的是，在周围胶合体（动型石）区域组装了广泛的粘着蛋白增强结构域，在那里它们促进了染色体生物的生物学和抗拒早熟的姐妹染色质被分离。我们先前表明，萌芽的酵母动物学直接的周围胶粒粘着蛋白结构域。我们的初步数据表明，周围胶粒粘着素结构域是通过成核和扩散机制表观遗传组装的。我们通过确定与丝粒相邻的环形成是否会以远端序列阻碍粘着蛋白的募集来测试该模型的真实性。丁香粒染色质也将被分离出来，其蛋白质组成在无偏筛选中的蛋白质成分是针对动力学相关因子或表观遗传染色质修饰的，该因子将直接粘着蛋白结构域组成。最后，限制凝聚素募集的绝缘子将用于描述高保真染色体传播所需的最低效率有效的果粒域。初步数据还表明，粘蛋白分布是由SCC2/SCC4粘着蛋白加载子与基因间序列的先前关联指导的。在第二个目标中，我们努力确定染色体臂上装载器和粘着素定位的机理和重要性。 RSC ATP依赖性染色质重塑剂，SCC2/SCC4和粘着素的缔合的顺序和相互依赖性将在染色体ARM粘连相关区域上确定，以剖析粘蛋白沉积的疾病。在聚合酶失活以及RNA聚合酶II转录终止突变体中，将检查RNA聚合酶II依赖性转录在建立粘着蛋白负载子分布中的贡献，以及在RNA聚合酶II转录终止突变体中的机制和意义，以划定转录和坐体定位之间的关系性质。萌芽酵母粘着素在促进RNA聚合酶II转录终止中的作用将使用条件粘着蛋白突变体确定。 公共卫生相关性：在每个细胞分裂期间，染色体必须准确地重复并隔离到子细胞，并且这些事件中的错误可能导致癌症或遗传疾病，例如唐氏综合症。将复制的染色体或姐妹染色质被的准确分离与子细胞的精确分离，要求姐妹在整个细胞周期的大部分时间里彼此之间彼此之间的物理相关。在此应用中，我们努力了解介导姐妹染色质酸的物理缔合的蛋白质（称为粘着蛋白）如何招募到染色体上的适当位置以介导染色体分离，DNA修复和基因调节，每种蛋白质对于维持基因组完整性都是重要的。