Transcriptome regulation during mitosis

摘要 在细胞分裂过程中，准确地将染色体分离到子代细胞对细胞活力至关重要。 和正常发育。染色体分离错误与癌症进展和病因有关 一些类型的严重出生缺陷(例如唐氏综合症)。染色体分离是由 有丝分裂/减数分裂纺锤体，这是一个大的大分子结构，主要由微管和 相关蛋白质。染色体的运动是由微管附着在着丝粒上提供动力的。 动粒-微管连接错误导致非整倍体。几十年的工作已经确定了许多 对有丝分裂纺锤体的组装和功能很重要的蛋白质，但仍有许多未知之处 关于主轴装配的调节。我们实验室和其他实验室最近的研究表明，除了 蛋白质，数百种不同的mRNAs和翻译装置的组件，以及长的非编码 RNAs也定位于有丝分裂的纺锤体和染色体，并在动粒和纺锤体中发挥作用。 集合。我们的团队和其他人最近也证明了着丝粒被转录成长的， 非编码RNA对动粒的组装和功能很重要。我们证明了lncRNA与AND结合 激活有丝分裂激酶Aurora-B。在这项提案中，我们描述了一系列旨在阐明 有丝分裂过程中定位于纺锤体和染色体的RNA的作用和机制。我们提出了一个 研究着丝粒蛋白如何促进着丝粒重复序列转录的一系列实验 有丝分裂及其与动粒-微管附着变化的关系。然后，我们提出了一系列 详细的生化实验，以了解各种着丝粒蛋白如何与RNA相互作用以及如何 这种相互作用会影响它们的着丝粒功能。除了受新近结合的RNA调控外 研究表明，在有丝分裂过程中，Aurora-B控制着非编码RNA与染色体的结合。 最后，我们建议研究Aurora-B促进lncRNAs从 有丝分裂染色体。我们重点研究Aurora-B和hnRNP U之间的相互作用以及A 在有丝分裂过程中未能从染色体上移除IncRNAs。总而言之，这些目标将提供洞察力 Aurora-B与纺锤体、染色质和动粒定位的RNA的相互作用以及这些 相互作用导致成功的染色体分离。这些研究可能会提供基本的 深入了解纺锤体组装和细胞分裂的机制，并可以提供更多关于 癌症进展的机制和出生缺陷的原因。

Abstract Accurate segregation of chromosomes to daughter cells during cell division is critical for cell viability and normal development. Errors in chromosome segregation are correlated with cancer progression and cause some types of severe birth defects (e.g. Down Syndrome). Chromosome segregation is controlled by the mitotic/meiotic spindle, which is a large macromolecular structure composed primarily of microtubules and associated proteins. Chromosome movements are powered by attachment of microtubules to the kinetochore and errors in kinetochore-microtubule attachment lead to aneuploidy. Decades of work have identified many proteins that are important for the assembly and function of the mitotic spindle, yet much remains unknown about regulation of spindle assembly. Recent work from our lab and others has shown that in addition to proteins hundreds of different mRNAs and components of the translation apparatus as well as long noncoding RNAs are also localized to the mitotic spindle and chromosomes and play a role in kinetochore and spindle assembly. Our group and others have also recently demonstrated that centromeres are transcribed into a long, noncoding RNA important for kinetochore assembly and function. We showed that lncRNAs bind to and activate the mitotic kinase Aurora-B. In this proposal we describe a series of experiments designed to elucidate the roles and mechanisms of RNAs localized to the spindle and chromosomes during mitosis. We propose a series of experiments to examine how kinetochore proteins promote transcription of centromeric repeats during mitosis and how this is related to changes in kinetochore-microtubule attachment. We then propose a series of detailed biochemical experiments to understand how various centromere proteins interact with RNA and how this interaction influences their centromere functions. In addition to being regulated by RNA binding recent work demonstrates that Aurora-B controls the binding of noncoding RNAs to the chromosomes during mitosis. In the final Aim we propose to study the mechanism by which Aurora-B promotes the release of lncRNAs from mitotic chromosomes. We focus on the interaction between Aurora-B and hnrnp U and the consequences of a failure to remove lncRNAs from chromosomes during mitosis. Taken together, these Aims will provide insight into the interaction of Aurora-B with spindle, chromatin, and kinetochore-localized RNAs and how these interactions lead to successful chromosome segregation. These studies are likely to provide fundamental insight into the mechanisms of spindle assembly and cell division and could provide additional insight into mechanisms of cancer progression and the cause of birth defects.