RNA Transport Within the Nucleus

描述(申请人提供)：这项研究项目涉及一个团队 两位细胞生物学家和一位生物物理学家卓有成效地合作 最近和现在正在联合起来进行rna定位的研究。 以及细胞核内的交通。这项拟议的研究实际上是独一无二的 核内RNA的运动是在活细胞中跟踪的，而不是通过需要化学固定的定位方法。这件事的重要性 方法怎么夸大都不为过，因为它打开了体内 核内RNA转运的动态途径的研究。两大 要采取的实验策略，都是在P.I.S实验室开发的， 是内源性核RNA的荧光标记和显微注射 将荧光RNA送入哺乳动物的细胞核。一个基于扩散的模型 核RNA传输已经从这一初步工作中出现，这将是 进一步调查。拟议的研究将详细说明 核糖体RNA和β-珠蛋白的核内转运模式 C-fos mRNAs。突变的β-珠蛋白RNA将被研究以进行相关处理 缺陷对核内运输和定位的影响。研究也将是 进行剪接和多腺化但核限制的RNA，Xist， 这是一种由不活跃的X染色体产生的不寻常的转录本， 预测显示出非常不同的核内传输特性 MRNAs。该项目的另一个方面将解决核内交通问题 这些RNA与已知参与核进口或核进口的蛋白质有关 RNA输出，即Ran-GTP酶和TAP。

DESCRIPTION (provided by applicant): This research project involves a team of two cell biologists and a biophysicist who have productively collaborated recently and now are joining together to undertake studies of RNA localization and traffic in the cell nucleus. The proposed research is virtually unique in that intranuclear RNA movements are tracked in living cells, rather than by localization methods that require chemical fixation. The importance of this approach cannot be overstated, since it opens the door to the in vivo investigation of dynamic pathways of intranuclear RNA transport. The two major experimental strategies to be taken, both developed in the P.I?s laboratory, are the fluorescent tagging of endogenous nuclear RNAs and the microinjection of fluorescent RNAs into mammalian cell nuclei. A diffusion-based model for nuclear RNA transport has emerged from this initial work and this will be further investigated. The proposed studies will characterize in detail the intranuclear trafficking patterns of ribosomal RNA as well as beta-globin and c-fos mRNAs. Mutant beta-globin RNAs will be investigated to relate processing defects to intranuclear transport and localization. Studies will also be undertaken of the spliced and polyadenylated but nucleus-restricted RNA, Xist, which is an unusual transcript produced by the inactive X chromosome and is predicted to display very different intranuclear transport properties than mRNAs. Another aspect of the project will address the intranuclear traffic of these RNAs in relation to proteins known to be involved in nuclear import or RNA export, i.e. the Ran-GTPase and TAP.