YEAST GENES IN RNA PROCESSING & NUCLEUS/CYTOSOL EXCHANGE

RNA 加工中的酵母基因

• 批准号: 7148140
• 负责人: Anita K Hopper
• 金额: $ 23.5万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-09-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7148140
• 关键词: RNA splicing; Saccharomyces cerevisiae; acetylation; acyltransferase; aminoacid metabolism; biological signal transduction; carbohydrate metabolism; cell nucleus; cytoplasm; enzyme activity; fungal genetics; gene expression; gene mutation; genetic regulation; green fluorescent proteins; heterokaryon; intracellular transport; introns; membrane proteins; nuclear membrane; posttranscriptional RNA processing; protein biosynthesis; protein structure function; transfer RNA

DESCRIPTION (provided by applicant): The presence of organelles, areas of biochemical specialization, separated from one another other by membranes, characterize eukaryotic cells. Such cellular organization necessitates elaborate mechanisms to effectively deliver the correct macromolecules to the correct locations, under the appropriate conditions, as well as mechanisms for the biogenesis, maintenance and inheritance of the organelles. Our focus is on the nucleus. Using genetic approaches available for our model eukaryotic organism, yeast Saccharomyces cerevisiae we previously identified Los1p. Los1p and its homologues (Xpo-t) function in tRNA nuclear egress. However, LOS1/Xpo-t is an unessential gene in all organisms that it has been possible to ablate its function, requiring that cells possess Los1p-independent tRNA nuclear export pathway(s). Aim 1 of the proposed work employs both candidate and genome-wide technologies to uncover the Los1p-independent tRNA nuclear export pathway(s). Until recently tRNA movement was regarded to be unidirectional from the nuclear site of synthesis to the cytosolic site of function. However, we discovered that the reverse also occurs. In fact, large pools of tRNA imported from cytoplasm quickly and reversibly reside in the nucleus under particular physiological conditions or in particular yeast mutants. This "retrograde tRNA nuclear import pathway" is likely a newly discovered level of gene expression for all eukaryotic organisms. Aim 2 seeks to understand the mechanisms that govern the retrograde pathway and its coordination with cellular metabolism. In Aim 3 we employ genome-wide approaches to learn how the complicated and dynamic nucleus is organized into domains that are not separated from each other by membranes. To date, we discovered necessary roles for N-acetylation and an integral membrane protein to appropriately tether our reporter to the inner nuclear membrane. We seek to identify other such gene products and to learn whether those already identified fulfill general roles in subnuclear organization. We anticipate that the information gleaned will have significant application in human disorders, such as cancers, Emery-Dreifuss muscular dystrophy and Hutchison-Gilford Progeria syndrome that result from inappropriate nucleus/cytosol dynamics and nuclear organization.

描述（由申请人提供）：细胞器的存在，即生物化学特化区域，通过膜彼此分开，是真核细胞的特征。这种细胞组织需要复杂的机制来在适当的条件下有效地将正确的大分子传递到正确的位置，以及细胞器的生物发生、维持和遗传的机制。我们的重点是核心。使用可用于我们的模型真核生物（酿酒酵母）的遗传方法，我们之前鉴定出了 Los1p。 Los1p 及其同源物 (Xpo-t) 在 tRNA 核出口中发挥作用。然而，LOS1/Xpo-t 在所有生物体中都是非必需基因，其功能有可能被消除，从而要求细胞拥有不依赖于 Los1p 的 tRNA 核输出途径。拟议工作的目标 1 采用候选技术和全基因组技术来揭示不依赖于 Los1p 的 tRNA 核输出途径。直到最近，tRNA 运动还被认为是从核合成位点到细胞质功能位点的单向运动。然而，我们发现相反的情况也会发生。事实上，在特定的生理条件下或在特定的酵母突变体中，从细胞质输入的大量 tRNA 会快速且可逆地驻留在细胞核中。这种“逆行 tRNA 核输入途径”可能是所有真核生物新发现的基因表达水平。目标 2 旨在了解控制逆行途径的机制及其与细胞代谢的协调。在目标 3 中，我们采用全基因组方法来了解复杂且动态的细胞核如何组织成彼此不被膜分隔的域。迄今为止，我们发现了 N-乙酰化和整合膜蛋白的必要作用，以将我们的报告基因适当地束缚到内核膜上。我们试图鉴定其他此类基因产物，并了解那些已鉴定的基因产物是否在亚核组织中发挥一般作用。我们预计收集到的信息将在人类疾病方面具有重要应用，例如癌症、Emery-Dreifuss 肌营养不良症和 Hutchison-Gilford 早衰综合症，这些疾病是由不适当的细胞核/细胞质动力学和细胞核组织引起的。