Nuclear architecture in C. elegans

线虫的核结构

• 批准号: 7734289
• 负责人: Orna Cohen-Fix
• 金额: $ 16.46万
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7734289
• 关键词: Affect; Appearance; Architecture; Caenorhabditis elegans; Case Study; Cell Cycle; Cell Nucleus; Cells; Collection; Databases; Defect; Disease; Elements; Embryo; Eukaryota; Eukaryotic Cell; Gene Proteins; Genes; Genetic; Lamins; Lead; Libraries; Link; Lipids; Malignant Neoplasms; Monitor; Nuclear; Nuclear Envelope; Nuclear Pore; Nuclear Structure; Organelles; Pathway interactions; Pattern; Phenotype; Play; Premature aging syndrome; Process; Proteins; RNA Interference; Regulation; Role; Saccharomycetales; Shapes; Structure; Yeasts; base; genetic regulatory protein; insight; interest; lipid biosynthesis; lipine; size

The nucleus is arguably one of the most important organelles in the cell, and yet surprisingly little is known about how its shape is maintained and what determines its size. The importance of nuclear shape is underscored by the fact that various diseases, including cancer and premature aging, are associated with changes in nuclear shape, and yet the relationship between nuclear shape and nuclear function is poorly understood. The nuclear envelope undergoes cycles of assembly and disassembly in each and every cell cycle, and one of the key outstanding questions in the field is which proteins facilitate these processes. To gain insight into nuclear envelope dynamics we initiated the C. elegans nuclear architecture project. This project has two main components: (a) to examine in C. elegans the role of proteins identified in a yeast screen as being involved in nuclear architecture; and (b) to screen for additional gene/proteins involved in determining nuclear shape and size, and in affecting nuclear envelope breakdown and reassembly. In the past yeast we have made significant progress on both these fronts, as described below. (a)to examine in C. elegans the role of proteins identified in a yeast screen as being involved in nuclear architecture. We have previously shown that the lipin pathway, which regulates lipid biosythesis, is involved in maintaining proper nuclear structure. Since yeast nuclei and nuclei of higher eukaryotes differ in several important aspects (e.g. nuclear envelope breakdown, which does not occur in budding yeast, and the presence of lamins, which are absent in yeast), we determined whether lipin plays a similar role in maintaining nuclear integrity in C. elegans. Our findings indicate that down regulating lipin leads to aberrant ER structure (as in yeast) and to defects in nuclear envelope assembly and disassembly. These findings validate our approach for using yeast as a starting point for uncovering proteins involved in nuclear architecture in higher eukaryotes, and it contributes to our understanding of the function of lipin in metazoa. (b) to screen for additional gene/proteins involved in determining nuclear shape and size, and in affecting nuclear envelope breakdown and reassembly. To this end we constructed a C. elegans strain with which we can monitor nuclear dynamics. To screen for proteins that affect nuclear architecture we treated this strain with RNAi from an RNAi collection of roughly 2000 genes known to cause embryonic lethality when inactivated. So far we have screen 200 genes, of which 25% gave an interesting nuclear pattern, including the appearance of multiple nuclei, defects in nuclear shape and defects in nuclear pore distribution. We are in the process of completing this screen and assembling a data base of genes that affect nuclear dynamics based on common phenotypes. Genes whose RNAi treatment result in an informative phenotype will be pursued further.

细胞核可以说是细胞中最重要的细胞器之一，但令人惊讶的是，人们对它的形状如何保持以及是什么决定了它的大小知之甚少。核形状的重要性是由以下事实强调的：各种疾病，包括癌症和过早衰老，与核形状的变化有关，但核形状和核功能之间的关系知之甚少。核膜在每个细胞周期中都经历组装和拆卸的循环，该领域的一个关键问题是哪些蛋白质促进了这些过程。为了深入了解核膜动力学，我们启动了C。elegans核建筑项目。这个项目有两个主要组成部分：（一）在C。在酵母筛选中鉴定的参与核结构的蛋白质的作用;和（B）筛选参与决定核形状和大小以及影响核膜分解和重组的另外的基因/蛋白质。在过去的酵母中，我们在这两个方面都取得了重大进展，如下所述。 (a)to检查C。在酵母筛选中鉴定的蛋白质的作用与核结构有关。我们以前已经表明，脂蛋白途径，调节脂质生物合成，参与维持适当的核结构。 由于酵母细胞核和高等真核生物的细胞核在几个重要方面不同（例如，核被膜破裂，这在芽殖酵母中不会发生，核纤层蛋白的存在，这在酵母中是不存在的），我们确定脂蛋白是否在维持C.优雅的我们的研究结果表明，下调脂蛋白导致异常的ER结构（如在酵母）和核被膜组装和拆卸的缺陷。这些研究结果验证了我们的方法，使用酵母作为一个起点，揭示蛋白质参与核结构在高等真核生物，它有助于我们的理解的功能，脂蛋白在后生动物。 (b)筛选参与决定核形状和大小以及影响核膜破裂和重组的其他基因/蛋白质。为此，我们构建了一个C。我们可以用它来监测核动力学。为了筛选影响核结构的蛋白质，我们用来自大约2000个已知在失活时导致胚胎致死的基因的RNAi集合的RNAi处理该菌株。到目前为止，我们已经筛选了200个基因，其中25%的基因给出了有趣的核模式，包括多个核的出现，核形状的缺陷和核孔分布的缺陷。我们正在完成这项筛选工作，并根据常见的表型组装一个影响核动力学的基因数据库。将进一步追求其RNAi治疗导致信息表型的基因。