Architecture of the Diffusion Barrier in the Nuclear Pore Complex

核孔复合体中扩散势垒的结构

• 批准号: 7383441
• 负责人: MICHAEL F REXACH
• 金额: $ 33.26万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA CRUZ
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-28 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7383441
• 关键词: Adopted; Amino Acids; Animal Model; Architecture; Asses; Behavior; Binding; Biochemical; Biochemistry; Biological; Biological Assay; Biophysics; Caliber; Cells; Cellular biology; Collection; Communication; Cytoplasm; Cytoplasmic Protein; Diffusion; Disease; Environment; Eukaryota; Eukaryotic Cell; Family; Filament; Genetic; Glycine; In Situ; In Vitro; Individual; Knowledge; Learning; Life; Locales; Location; Maps; Molecular; Molecular Machines; Names; Nuclear Magnetic Resonance; Nuclear Pore Complex; Nuclear Pore Complex Proteins; Nucleoplasm; Operative Surgical Procedures; Permeability; Phenylalanine; Proteins; Recombinants; Research; Role; Saccharomyces cerevisiae; Scientist; Shapes; Solutions; Structure; Techniques; Technology; Tertiary Protein Structure; Testing; Yeasts; aqueous; genetic manipulation; in vivo; insight; molecular modeling; nanometer; novel; particle; porin; professor; receptor; research study; seal; size; structural biology; three dimensional structure; trafficking

DESCRIPTION (provided by applicant): The nuclear pore complex (NPC) is one of the most important molecular machines in eukaryotes because it gates the porous conduits between the cytoplasm and nucleoplasm of cells and controls all nucleo-cytoplasmic traffic and communication. Its most important architectural feature is a poorly understood semi-permeable diffusion barrier in its center that maintains a tight seal against cytoplasmic proteins as small as 4 nanometers in size, but opens to allow facilitated transport of particles of all shapes and sizes up to 40 nanometers in size. This flexible barrier is composed of a family of filamentous proteins named FG nucleoporins (FG nups) that feature large unfolded domains in their native functional state, which are decorated with multiple phenylalanine glycine motifs (FG domains). The specific aims of our proposed research are to 1) characterize the dynamic structure and intra-molecular interactions of FG domains representing two different types of FG nup filaments that are anchored at three different locales of the NPC, and 2) test the hypothesis that inter-molecular associations between FG domains of nups create a filamentous meshwork structure at the NPC center, which establishes the size-selective barrier to the passive diffusion of proteins. The proposed experiments will combine biochemical, biophysical, cell biological, structural (Nuclear Magnetic Resonance), and molecular modeling techniques to gain insight into the dynamic behavior, structure and function of the FG nups. We will also gain fundamental knowledge on the dynamic behavior and structure of disordered domains of proteins in general.

描述（由申请人提供）：核孔复合体（NPC）是真核生物中最重要的分子机器之一，因为它门控细胞的细胞质和核质之间的多孔管道并控制所有核质运输和通讯。其最重要的结构特征是其中心有一个人们知之甚少的半渗透性扩散屏障，该屏障对尺寸小至 4 纳米的细胞质蛋白保持紧密密封，但打开后可促进尺寸高达 40 纳米的各种形状和尺寸的颗粒的运输。这种灵活的屏障由名为 FG 核孔蛋白 (FG nups) 的丝状蛋白家族组成，其天然功能状态下具有大的未折叠结构域，并装饰有多个苯丙氨酸甘氨酸基序（FG 结构域）。我们提出的研究的具体目的是1）表征代表两种不同类型的FG nup细丝的FG域的动态结构和分子内相互作用，这些细丝锚定在NPC的三个不同位置；2）测试这样的假设：nups的FG域之间的分子间关联在NPC中心创建丝状网状结构，该结构建立了针对被动的尺寸选择性屏障 蛋白质的扩散。拟议的实验将结合生物化学、生物物理、细胞生物学、结构（核磁共振）和分子建模技术，以深入了解 FG nups 的动态行为、结构和功能。我们还将获得有关蛋白质无序结构域的动态行为和结构的基础知识。