Dissecting the role of the nuclear basket in regulating mRNA metabolism

调节其基因的表达是任何生物体的基本任务。在真核细胞中，遗传信息储存的地方，即细胞核，和信息被翻译成蛋白质的地方，即细胞质，被一层双层脂质膜隔开，大分子无法渗透。在储存DNA的细胞器细胞核中，遗传信息首先被复制成信使分子，信使分子必须离开细胞核，到达细胞质，然后被翻译成蛋白质。到达蛋白质合成位点的唯一途径是通过核孔复合物（NPC），这是一种嵌入核膜的大分子复合物。我们研究计划的长期目标是了解与mRNA结合的不同因子与组成NPC的因子之间的相互作用如何有效和选择性地控制mRNA从细胞核向细胞质的输出。为了进一步深入了解这一重要过程，我们将使用不同的生物物理、生化和遗传工具。首先，我们将使用最近开发的超分辨率显微镜技术，以纳米分辨率实时跟踪单个mRNA分子，以确定核筐（mRNA到达核外围时遇到的第一个结构）如何调节mRNA进入NPC。此外，利用基因组学和蛋白质组学分析，我们将研究细胞如何诱导NPC组成的变化，从而在细胞暴露于压力时改变基因表达程序。通过完成该项目，我们将揭示这一基本细胞过程背后的重要机制细节，并建立与单分子分辨率研究不同细胞过程相关的生物物理工具。

Regulating the expression of its genes is an essential task for any living organism. In eukaryotic cells, the site where the genetic information is stored, the nucleus, and the site where the information is translated into protein, the cytoplasm, is separated by a double bilipidic membrane, impermeable to large molecules. In the nucleus, the organelle where DNA is stored, the genetic information is first copied into a messenger molecule, called mRNA, which has to exit the nucleus and reach the cytoplasm to get translated into proteins. The only path to reach the site of protein synthesis is through the nuclear pore complex (NPC), a large macromolecular complex embedded in the nuclear membrane. The long-term objective of our research program is to understand how the interplay between different factors that bind to the mRNA and factors composing the NPC control efficient and selective export of mRNAs from the nucleus to the cytoplasm. To gain further insight into this essential process, we will use different biophysical, biochemical and genetic tools. First, we will use recently developed super resolution microscopy techniques that allow to follow individual mRNA molecules in real time and in nanometer resolution to determine how nuclear basket, the first structure mRNAs encounter when reaching the nuclear periphery, regulates the access of mRNPs to the NPC. Furthermore, using genomic and proteomic assays, we will investigate how cells induce changes in the composition of the NPC to change gene expression programs when cells are exposed to stress. By completing this project we will reveal important mechanistic details that underlie this essential cellular process and establish biophysical tools relevant to study different cellular processes in single molecule resolution.