Biochemical and cellular functions of Karyopherins - Revision - 1

核传递蛋白的生化和细胞功能 - 修订版 - 1

• 批准号: 10555037
• 负责人: Yuh Min Chook
• 金额: $ 2.34万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-11 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10555037
• 关键词: Antineoplastic Agents; Binding; Biochemical; Bioinformatics; Biological; Cell Nucleus; Cell physiology; Cells; Chemicals; Collection; Complex; Cytoplasm; Development; Disease; Exportins; Food and Drug Administration Drug Approval; Foundations; Gene Expression; Grant; Histones; Importins; Karyopherins; Knowledge; Learning; Ligands; Light; Maps; Mediating; Messenger RNA; Molecular Chaperones; Nuclear; Nuclear Export; Nuclear Import; Nuclear Localization Signal; Nucleosomes; Pathway interactions; Peptide Signal Sequences; Proline; Proteins; Proteome; RNA-Binding Proteins; Signal Transduction; Tyrosine; Work; design; experimental study; inhibitor; mRNA Export; prevent; protein transport; receptor

Abstract of grant R35GM141461: Twenty homologous Karyopherin- (Kap) proteins mediate the majority of protein transport between the nucleus and the cytoplasm. The Chook Lab is a leader in understanding the mechanisms by which Kaps control macromolecular traffic. We achieve this understanding through a combination of structural, biochemical, cell biological and bioinformatic analyses of Kap-ligand interactions. Our studies of the nuclear import receptor Kapβ2 led to discovery of the proline-tyrosine nuclear localization signal (PY-NLS), which it recognizes. This study led to a new concept—that many nuclear targeting signals are defined not merely by sequence but by a collection of physical features—which explained how Kapβ2 can recognize hundreds of different sequences, and enabled us to design the first nuclear import inhibitor. Although two additional NLS types have recently been determined, cargo recognition by most importins, including Importins-4, -7, -8, -9 and -11 is not understood even though they account for 50% of nuclear import. Few of their cargos are known and the NLS classes that they recognize are unknown. The missing knowledge obscures our understanding of how a significant portion of the proteome lacking recognizable NLSs are trafficked into the nucleus. We aim to discover new cargos, classes of NLSs and pathway-specific inhibitors for all importins. We will combine this knowledge with bioinformatic analyses and experiments to define the full cargo repertoires of each importin, and thus map both the traffic and cellular processes that they each control. We showed that in addition to mediating nuclear import, importins also act as chaperones. We will learn how Kap2 chaperones RNA-binding proteins, preventing their aggregation and understand the functional significance of the Importin-9 histone-chaperone function in histone storage and nucleosome assembly. In our studies of nuclear export, we were the first to reveal how CRM1 recognizes the only known nuclear export signal (NES). This work was foundational for development of the anti-cancer drug Selinexor, and the physical/chemical mechanisms of inhibition that we later revealed contributed to FDA-approval of the drug. We also revealed the sequence and structural degeneracy of the NES, explaining how CRM1 is able to recognize hundreds of diverse NES sequences. CRM1 also exports thousands of mRNAs, but little is known about the mechanism. We will study CRM1-mRNA export complexes to shed light on this critical step of gene expression. Finally, we will expand study to the exportin Msn5, which binds intrinsically disordered and phosphorylated segments of multiple cargos. This work will reveal a second, new class of NES.

授予摘要R35GM141461： 20个同源的Karyopherin-(KAP)蛋白介导了大部分蛋白质的转运 在细胞核和细胞质之间。朱克实验室是理解 KAP控制大分子流量的机制。我们做到了这一点 通过结合结构、生化、细胞生物学和生物信息学分析 KAP-配体相互作用。我们对核进口受体KAPβ2的研究导致发现 它识别的脯氨酸-酪氨酸核定位信号(PY-NLS)。这项研究导致了 到了一个新的概念，即许多核靶向信号不仅仅是由序列定义的 而是通过一组物理特征-这解释了KAPβ2如何识别数百个 不同的序列，并使我们能够设计出第一个核进口抑制物。虽然 最近确定了另外两种NLS类型，大多数重要因子识别货物， 包括Importins-4、-7、-8、-9和-11，尽管它们占50%，但仍不被理解 核进口的数量。他们的货物很少为人所知，他们认识的NLS类别是 未知。缺失的知识模糊了我们对很大一部分 缺乏可识别的NLSS的蛋白质组被运输到细胞核。我们的目标是发现 新的货物，NLSS的类别和所有重要蛋白的特定途径抑制物。我们将联合起来 这一知识与生物信息学分析和实验相结合，以定义完整的货物剧目 并因此映射它们各自控制的流量和蜂窝进程。 我们发现，除了调节核进口外，进口素还扮演着伴侣的角色。 我们将学习KAP2是如何伴随核糖核酸结合蛋白，阻止其聚集和 了解组蛋白中Importin-9组蛋白伴侣功能的功能意义 储存和核小体组装。在我们的核出口研究中，我们最先揭示了 CRM1如何识别唯一已知的核出口信号(NES)。这项工作是 抗癌药物Selinexor及其物理化学的开发基础 我们后来揭示的抑制机制有助于FDA批准该药物。我们 还揭示了NES的序列和结构简并，解释了CRM1是如何 能够识别数百种不同的NES序列。CRM1还出口数千台 MRNA，但对其机制知之甚少。我们将研究CRM1-mRNA的输出 以阐明基因表达的这一关键步骤。最后，我们将扩大研究范围 与Exportin MSN5结合，它结合了固有的无序和磷酸化的片段 多批货物。这项工作将揭示第二类新的NES。