MECHANISM OF MACROMOLECULAR EXPORT FROM THE NUCLEUS

从细胞核输出大分子的机制

• 批准号: 6525460
• 负责人: KARSTEN WEIS
• 金额: $ 19.56万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 2004-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6525460
• 关键词: RNA binding protein; Saccharomyces cerevisiae; biological signal transduction; fungal genetics; guanosinetriphosphatases; in situ hybridization; intracellular transport; messenger RNA; molecular cloning; nuclear membrane; nucleic acid sequence; protein structure function; protein transport; site directed mutagenesis; transport proteins; yeast two hybrid system

DESCRIPTION (adapted from the applicant's abstract): Export of RNA and protein from the nucleus into the cytoplasm is a fundamental cellular process and a key step in the control of eukaryotic gene expression. The mechanisms governing these transport events are still poorly understood but kinetic competition studies in Xenopus oocytes have indicated that different RNA classes, including mRNA, snRNA, tRNA and rRNA use distinct export pathways. Since most, if not all RNAs, are associated with proteins in the nucleus it was suggested that RNA export events are mediated by proteins in the nucleus it was suggested that RNA export events are mediated by proteins containing appropriate nuclear export signals (NESs). This is supported by the identification of small transferable signals in proteins that cause their rapid and active export from the nucleus. The long-term goal of the proposed research is to characterize different RNA and protein export pathways in the yeast S. cerevisiae and to understand the nuclear export mechanisms at a molecular level. More specifically, three specific aims are proposed: (1) The P.I. will characterize the nuclear export factor export in 1 (Xpo1p/Crm1p) and its role in mRNA export. A variety of biochemical and genetic approaches will be used to identify factors which interact with Xpo1p. The role of the GTPase Ran in regulating the interaction of Xpo1p with other cellular factors will be examined and the adapter(s) that mediate(s) Xpo10,s role in mRNA export will be characterized. (2) The NES-mediated nuclear protein export machinery will be dissected. Genetic approaches will be explored to identify additional components of the NES-protein export machinery. This export pathway will be used as a model system to understand the molecular details of how macromolecules are transported through the nuclear pore complex into the cytoplasm. (3) Finally, the P.I. will determine whether distinct RNA export pathways exist in yeast. In situ labeling in fixed and live cells will be used to characterize the export of the different RNA classes in several mutant backgrounds. If distinct pathways are identified, factors that mediate and regulate these export events will be identified.

描述（改编自申请人的摘要）：RNA的导出和 从细胞核到细胞质的蛋白质是基本细胞 控制真核基因表达的过程和关键步骤。这 管理这些运输事件的机制仍然很了解 但是在异爪蟾卵母细胞中的动力学竞争研究表明 不同的RNA类，包括mRNA，snRNA，tRNA和rRNA使用不同 出口途径。由于大多数（如果不是全部RNA）都与蛋白质有关 在细胞核中，建议RNA输出事件是由 核中的蛋白质提出RNA输出事件是 由含有适当的核出口信号（NESS）的蛋白质介导。 这是通过在 引起其从细胞核中快速而活跃的导出的蛋白质。这 拟议的研究的长期目标是表征不同的RNA 和酵母菌酿酒酵母中的蛋白质出口途径并了解 分子水平的核输出机制。更具体地说， 提出了三个具体目标：（1）P.I。将表征 1（XPO1P/CRM1P）中的核出口因子导出及其在mRNA中的作用 出口。各种生化和遗传方法将用于 确定与XPO1P相互作用的因素。 GTPase的作用在 调节XPO1P与其他细胞因子的相互作用将是 检查和介导XPO10的适配器在mRNA导出中的作用 将被描述。 （2）NES介导的核蛋白出口 将解剖机械。遗传方法将被探讨 确定NES蛋白导出机械的其他组件。这 出口途径将用作模型系统，以了解分子 大分子如何通过核孔传输的细节 复合物进入细胞质。 （3）最后，P.I.将确定是否 酵母中存在不同的RNA导出途径。固定的原位标签和 活细胞将用于表征不同RNA的导出 在几个突变背景中的课程。如果不同的途径是 确定，调节和调节这些出口事件的因素将是 确定。