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

基本信息

批准号：
8368800
负责人：
PAUL Connor MEGEE
金额：
$ 28.7万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-07-01 至 2014-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8368800
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 chromatin remodeling cohesin cohesion daughter cell design insight interest mutant novel protein complex public health relevance research study segregation transcription termination transmission process tumorigenesis

项目摘要

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.

描述（由申请人提供）：准确的染色体分离对于将遗传信息成功传递给子细胞至关重要，这一过程的缺陷与流产、先天性疾病和肿瘤发生有关。正确的染色体分离不可或缺的是复制的姐妹染色单体的凝聚力或物理关联，这是由进化上保守的凝聚蛋白复合物介导的。粘连蛋白不仅参与染色体分离，还在DNA修复和基因调控中发挥重要作用。粘连蛋白在芽殖酵母染色体上的空间分布具有高度可重复性，表明它在染色体结构和功能中发挥重要作用。粘连蛋白经常出现在聚合转录基因之间的基因间区域中，这表明粘连蛋白分布和转录之间的相互作用目前尚未表征。值得注意的是，广泛的富含粘连蛋白的结构域在着丝粒周围（动粒侧翼）区域组装，在那里它们促进染色体生物取向并抵抗早熟的姐妹染色单体分离。我们之前表明，出芽酵母着丝粒直接指导着丝粒周围的粘连蛋白结构域组装。我们的初步数据表明，着丝粒周围的粘连蛋白结构域是通过成核和扩散机制进行表观遗传组装的。我们在特定目标 1 中通过确定着丝粒附近的环形成是否阻碍远端序列中的粘连蛋白招募来测试该模型的准确性。还将分离着丝粒周围染色质，并通过无偏筛选来表征其蛋白质组成，以寻找着丝粒相关因子或指导粘连蛋白结构域组装的表观遗传染色质修饰。最后，限制粘连蛋白募集的绝缘体将用于描绘高保真度染色体传输所需的最低有效的着丝粒周围结构域。初步数据还表明，粘连蛋白分布是由 Scc2/Scc4 粘连蛋白装载机与基因间序列的先前关联所指导的。在第二个目标中，我们努力确定装载机和粘连蛋白在染色体臂上定位的机制和意义。 RSC ATP 依赖性染色质重塑剂、Scc2/Scc4 和粘连蛋白的关联顺序和相互依赖性将在染色体臂粘连蛋白相关区域确定，以剖析粘连蛋白沉积途径。在聚合酶失活后，将检查 RNA 聚合酶 II 依赖性转录在建立粘连蛋白装载机分布中的贡献，并检查 RNA 聚合酶 II 转录终止突变体中粘连蛋白重新分布的机制和意义，以描绘转录与粘连蛋白装载机分布之间关系的性质。粘连定位。出芽酵母粘连蛋白在促进 RNA 聚合酶 II 转录终止中的作用将使用条件粘连蛋白突变体来确定。