Nucleocytoplasmic Interactions and Dynamics in Emery-Dreifuss Muscular Dystrophy

埃默里-德莱福斯肌营养不良症的核细胞质相互作用和动力学

基本信息

批准号：
7488572
负责人：
Howard J Worman
金额：
$ 35.22万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-09-01 至 2012-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7488572
关键词：
Actins Affect Amino Acid Substitution Biological Models Bispecific Antibody 2B1 Cardiomyopathies Cell Nucleus Cells Centrosome Charcot-Marie-Tooth Disease Complex Cytoplasm Cytoskeleton Data Defect Disease Disruption Emery-Dreifuss Muscular Dystrophy Familial partial lipodystrophy Fibroblasts Fluorescence Genes Integral Membrane Protein Intermediate Filament Proteins Lamin Type A Lamins Lead Light Microscope Limb-Girdle Muscular Dystrophies Link Localized Membrane Membrane Proteins Methods Movement Muscle Fibers Muscle function Muscular Dystrophies Mutation Myopathy Natural regeneration Nuclear Nuclear Envelope Nuclear Inner Membrane Nuclear Lamin Nuclear Outer Membrane Nuclear Structure Organ Pathogenesis Pathologic Pathway interactions Photobleaching Positioning Attribute Process Progeria Protein Dynamics Proteins Research Personnel Scapuloilioperoneal Atrophy with Cardiopathy Striated Muscles Syndrome Techniques Thinking Tissues X-linked Emery-Dreifuss muscular dystrophy emerin env Gene Products migration mutant myogenesis programs

项目摘要

DESCRIPTION (provided by applicant): Emery-Dreifuss muscular dystrophy (EDMD) results from mutations in two genes. Autosomal dominant EDMD, and infrequent autosomal recessive cases, result from mutations in LMNA. LMNA encodes A-type nuclear lamins, which are intermediate filament proteins associated with the inner nuclear membrane. Xlinked EDMD results from mutations in EMD, which encodes an integral protein of the nuclear envelope inner membrane called emerin. A commonly observed phenomenon in EDMD is defects in nuclear structure; however, little is known about how these structural defects relate to abnormal function. An emerging body of evidence demonstrates that the inside of the nucleus is connected to the cytoskeleton by a complex of interacting proteins termed the LING complex. These proteins include lamins, SUNs, which are transmembrane proteins of the inner nuclear membrane, and nesprins, some of which are transmembrane proteins localized to the outer nuclear membrane. Nesprins in turn can interact with cytoskeletal components such as actin. We hypothesize that mutations in the genes encoding A-type lamins and emerin cause a disruption of the LINC complex, which leads to abnormal nucleocytoskeletal connections and related defects in nuclear positioning and migration. Using a model system of fibroblasts undergoing polarization, we have obtained preliminary data showing that expression of lamin A mutants found in EDMD lead to nuclear movement defects. In Aim 1 of this project, we will carefully examine nuclear migration and centrosome positioning in cells expressing A-type lamins with amino acid substitutions that cause EDMD and related muscle disorders, cells lacking A-type lamins and cells expressing A-type lamins with amino acid substitutions that cause different diseases. In Aim 2, we will use fluorescence photobleaching techniques to determine the effects of mutations in A-type lamins on the dynamics of proteins of the LINC complex. In Aim 3, to link the pathogenic processes in autosomal EDMD to X-linked EDMD, we will examine the effects of emerin on nuclear movement and LINC complex protein dynamics. As nuclear positioning and nuclear migration are of critical importance in muscle fiber organization and differentiation, these studies will establish if defects in nucleocytoplasmic interactions lead to functional anomalies that can underlie the pathogenesis of autosomal and X-linked EDMD.

描述（由申请人提供）： emery-dreifuss肌肉营养不良（EDMD）是由两个基因突变引起的。常染色体显性EDMD和常染色体隐性病例是由LMNA突变引起的。 LMNA编码A型核层粘连，它们是与内部核膜相关的中间细丝蛋白。 Xlinked EDMD是由EMD突变引起的，EMD的突变编码了称为Emerin的核包膜内膜的积分蛋白。 EDMD中通常观察到的现象是核结构的缺陷。然而，对于这些结构缺陷与异常功能的关系知之甚少。新兴的证据表明，核的内部通过称为ling络合物的相互作用蛋白的复合物将其连接到细胞骨架。这些蛋白质包括层状，太阳，它们是内部核膜的跨膜蛋白和内斯蛋白，其中一些是固定在外核膜上的跨膜蛋白。 Nesprins反过来可以与诸如肌动蛋白等细胞骨架成分相互作用。我们假设编码A型层粘连蛋白和Emerin的基因中的突变会导致LINC复合物的破坏，从而导致核定细胞骨架连接异常，以及核定位和迁移的相关缺陷。使用经过极化的成纤维细胞模型系统，我们获得了初步数据，表明在EDMD中发现的层粘连蛋白A突变体的表达导致核运动缺陷。在该项目的AIM 1中，我们将仔细检查具有带有氨基酸取代的A型层粘连蛋白的细胞中的核迁移和中心体位置引起不同疾病的酸取代。在AIM 2中，我们将使用荧光光漂白技术来确定A型层素中突变对LINC复合物蛋白质动力学的影响。在AIM 3中，为了将常染色体EDMD的致病过程与X连锁EDMD联系起来，我们将研究烯象蛋白酶对核运动和linc复合蛋白动力学的影响。由于核定位和核迁移在肌肉纤维组织和分化中至关重要，因此这些研究将确定核质相互作用的缺陷是否导致功能异常，从而构成常染色体和X连接EDMD的发病机理的基础。