Structure-Function of the Nuclear Envelope Bridge and its Role in Laminopathies

核膜桥的结构-功能及其在核纤层蛋白病中的作用

• 批准号: 9325433
• 负责人: Thomas Schwartz
• 金额: $ 33.03万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9325433
• 关键词: ATP phosphohydrolase; Affect; Biochemical; Biological Process; Cancer Etiology; Cell Nucleus; Cells; Cerebellar Ataxia; Chromatin; Chromosome Pairing; Complex; Crystallization; Cytoplasm; Cytoskeleton; Data; Defect; Disease; Drug Targeting; Emery-Dreifuss Muscular Dystrophy; Employee Strikes; Etiology; Face; Funding; Future; Genes; Grant; Health; Human; Immunoglobulin Fragments; Lamin Type A; Lamin Type B; Lamins; Lead; Malignant Neoplasms; Mammalian Cell; Mechanics; Meiosis; Membrane Proteins; Molecular; Molecular Target; Multiprotein Complexes; Muscle; Muscular Dystrophies; Muscular dystrophy cardiomyopathy; Mutation; Nuclear; Nuclear Envelope; Nuclear Inner Membrane; Nuclear Lamina; Nuclear Outer Membrane; Nuclear Pore Complex; Pathologic; Patients; Peptides; Pharmaceutical Preparations; Positioning Attribute; Premature aging syndrome; Procedures; Process; Progeria; Proteins; Regulation; Research; Role; Scheme; Side; Signal Transduction; Specificity; Structure; The Sun; Therapeutic; Time; Tissues; TorsinA; Translating; Translations; Transport Process; United States; Wasting Syndrome; Work; antibody engineering; base; comparative; design; disease-causing mutation; emerin; env Gene Products; experimental study; human disease; insight; lissencephaly; migration; milligram; mimetics; new therapeutic target; programs; protein aggregate; protein complex; public health relevance; reconstitution; self assembly; tool; two-dimensional

DESCRIPTION (provided by applicant): In mammalian cells, A- and B-type lamins form a two-dimensional protein meshwork, the lamina, at the nucleoplasmic face of the nuclear envelope. Mutations scattered along the LMNA gene, which encodes A-type lamins, as well as mutations within other nuclear envelope proteins are associated with a broad range of human diseases collectively called laminopathies. The molecular etiology of these diseases remains unknown. Emery-Dreifuss muscular dystrophy (EDMD), the most prominent laminopathy, is an incurable, devastating muscular wasting disease, caused by mutations in either, the inner nuclear membrane (INM) protein emerin, laminA, or the outer nuclear membrane (ONM) KASH-proteins nesprins 1 and 2. The four proteins are connected via LINC complexes, evolutionary-conserved protein complexes between INM SUN-proteins and ONM KASH-proteins that bridge the faces of the nuclear envelope and physically connect the nuclear lamina to the cytoskeleton of mammalian cells. Taken together, the data suggests that EDMD is the result of aberrant nuclear positioning or, alternatively, aberrant mechanical signaling through the LINC complex. Furthermore, it has been shown that the overaccumulation of Sun1 at the INM is the pathological effector of EDMD. With funding through an exploratory R21 grant we have determined the core structure of the SUN-KASH complex in 2012, providing the first molecular insight into LINC complexes. Here, we build on this data and suggest a research program that should aid in the discovery of drug targets that hopefully will translate into a medication strateg for EDMD patients. This proposal outlines experiments that will lead A) to a comprehensive structural and biochemical understanding of the human SUN-KASH interactome, B) a structural basis for LINC complex anchorage to the lamin layer, and C) insight into the regulation of LINC complex assembly and disassembly. We expect that the pursuit of these three aims will yield a much better molecular description of the protein network that forms the basis of EDMD, and consequently will unveil possible drug targets that disrupt these processes. We further anticipate that this research will advance our understanding of the nuclear envelope in general, which will have a tangible impact on the vast array of pathological nuclear envelope disorders.

描述（由申请人提供）：在哺乳动物细胞中，A型和B型核纤层蛋白在核膜的核质面形成二维蛋白质网络，即核纤层。分布在编码 A 型核纤层蛋白的 LMNA 基因上的突变以及其他核膜蛋白内的突变与一系列统称为核纤层蛋白病的人类疾病有关。这些疾病的分子病因学仍然未知。 Emery-Dreifuss 肌营养不良 (EDMD) 是最常见的核纤层蛋白病，是一种无法治愈的毁灭性肌肉萎缩疾病，由内核膜 (INM) 蛋白 emerin、核纤层蛋白 A 或外核膜 (ONM) KASH 蛋白 nesprins 1 和 2 的突变引起。这四种蛋白通过进化保守的 LINC 复合物连接 INM SUN 蛋白和 ONM KASH 蛋白之间的蛋白质复合物，桥接核膜表面并将核纤层与哺乳动物细胞的细胞骨架物理连接。总而言之，数据表明 EDMD 是异常核定位的结果，或者是通过 LINC 复合体异常机械信号传导的结果。此外，研究表明，INM 处 Sun1 的过度积累是 EDMD 的病理效应子。在探索性 R21 资助的资助下，我们于 2012 年确定了 SUN-KASH 复合物的核心结构，首次提供了对 LINC 复合物的分子洞察。在这里，我们以这些数据为基础，提出了一项研究计划，该计划应有助于发现药物靶点，并有望转化为 EDMD 患者的药物治疗策略。该提案概述了实验，这些实验将导致 A) 对人类 SUN-KASH 相互作用组的全面结构和生化理解，B) LINC 复合物锚定于核纤层的结构基础，以及 C) 深入了解 LINC 复合物组装和拆卸的调节。我们预计，对这三个目标的追求将对构成 EDMD 基础的蛋白质网络产生更好的分子描述，从而揭示破坏这些过程的可能药物靶标。我们进一步预计这项研究将增进我们对核膜的总体理解，这将对大量病理性核膜疾病产生切实的影响。