Role of Condensin in Gene Regulation and Heterochromatin assembly in C. elegans

描述(申请人提供)：在每个细胞分裂过程中，基因组必须准确地复制并将一套完整的染色体分离到每个子细胞中。染色体分离和基因调控的失败会对人类健康造成严重后果，因为产生不适当染色体数目的细胞会导致非整倍体和染色体不稳定。染色体结构在促进准确的基因表达以避免癌症进展方面也起着关键作用。因此，了解染色体结构的各种调控机制是至关重要的，而我研究的长期目标是确定控制染色体结构的分子机制和机制，以确保基因组的稳定性。被称为凝聚素的保守多蛋白复合体是染色体结构的关键调节因子，越来越多的证据表明，凝聚素发挥着比之前认识到的更广泛的作用，包括基因沉默。在初步结果中，人们出人意料地发现凝聚素II在物理上与蛋白质相互作用，这些蛋白质与基于染色质的沉默相关，是转基因沉默现象所必需的。因此，这一建议旨在检验这一假设，即线虫有丝分裂凝集素II复合体与RNA干扰(RNAi)机制和染色质蛋白合作建立异染色质并调节基因表达。使用生化和遗传学方法：(1)凝聚素II、RNAi和染色质蛋白之间的明显相互作用将得到证实。此外，将对凝聚素相互作用蛋白进行测试，以确定它们是否有助于染色体分离以及凝聚素招募所必需的。(2)转基因检测将被用来研究相关形式的基于染色质的沉默是否需要凝聚素II。(3)它将确定小RNA是否与凝聚素II有关，以及是否是其在染色体组装中所需的功能。这些研究将提供关于这些保守机制如何确保染色体的准确构建、表达和分离以及避免在癌症中经常观察到的染色体异常的见解。

DESCRIPTION (provided by applicant): During every cell division, the genome must accurately replicate and segregate a complete set of chromosomes into each daughter cell. Failures in chromosome segregation and gene regulation have severe consequences for human health, since creating cells with an inappropriate chromosome number can lead to aneuploidy and chromosome instability. Chromosome structure also plays a key role in promoting accurate gene expression to avoid cancer progression. Therefore, it is of prime importance to understand the various mechanisms regulating chromosome structure, and the long-term goal of my research is to define the molecular machinery and mechanisms that govern chromosome structure to ensure genomic stability. Conserved multiprotein complexes known as condensins are key regulators of chromosome architecture, and increasing evidence suggests that condensins play broader roles than previously appreciated, including gene silencing. In preliminary results, it was unexpectedly discovered that condensin II physically interacts with proteins that are associated with chromatin-based silencing and required for transgene silencing phenomena. Thus, this proposal aims to test the hypothesis that the mitotic condensin II complex in Caenorhabditis elegans (C. elegans) cooperates with the RNA interference (RNAi) machinery and chromatin proteins to establish heterochromatin and mediate gene expression. Using biochemical and genetic approaches: (1) The apparent interactions between condensin II and RNAi and chromatin proteins will be confirmed. Moreover, condensin-interacting proteins will be tested to determine if they contribute to chromosome segregation and are required for condensin recruitment. (2) Transgene assays will be utilized to investigate whether condensin II is required for related forms of chromatin-based silencing. (3) It will determined if small RNAs associate with condensin II and are required for its functions in chromosome assembly. These studies will provide insights into how these conserved mechanisms ensure the accurate building, expression, and segregation of chromosomes and avoid the chromosomal abnormalities often observed in cancers.