The Role of LEM Domain Proteins in Nuclear Function

LEM 结构域蛋白在核功能中的作用

基本信息

批准号：
10439450
负责人：
PAMELA K. GEYER
金额：
$ 38.53万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-06-01 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10439450
关键词：
ATR checkpoint Adult Affect Binding Binding Proteins CHEK2 gene Cell Death Cell Maintenance Cells Cessation of life Chromatin Chromosomes Clustered Regularly Interspaced Short Palindromic Repeats Complex Cyst Cytology DNA DNA Damage Data Defect Deformity Development Disease Disease model Drosophila genus Failure Family Fatty acid glycerol esters Functional disorder Gene Expression Profile Genes Genetic Genome Germ Cells Health Heterochromatin High-Throughput RNA Sequencing Homeostasis Human Interphase Cell Lead Link Membrane Mitosis Monitor Mutation Nuclear Nuclear Envelope Nuclear Inner Membrane Nuclear Lamina Nuclear Structure Ontology Pathway interactions Phenotype Phosphotransferases Play Premature aging syndrome Proteins Role Shapes Signal Pathway Signal Transduction Skeletal Muscle Skin Stress Structural defect Structure Tertiary Protein Structure Testing Tissues Transcriptional Activation Variant adult stem cell barrier-to-autointegration factor base bone delta protein ds-DNA experimental study germline stem cells histone-binding proteins improved knock-down mutant novel overexpression prevent response sensor stem cell homeostasis stem cell population stem cell survival stem cells therapeutic development tool transcription factor transcriptome

项目摘要

ABSTRACT Human laminopathies are caused by mutations in genes encoding nuclear lamina (NL) proteins. These proteins form an extensive network that lies beneath the inner nuclear membrane. A unifying disease model suggests that lost tissue homeostasis is due to a failure to maintain adult stem cells. Although NL proteins responsible for laminopathies have been identified, it remains unclear how these proteins maintain healthy stem cell populations and promote tissue homeostasis. The conserved NL family of LEM-domain (LEM-D) proteins play a critical role in building nuclear structure and the NL. LEM-D proteins bind Barrier-to-Autointegration Factor (BAF), a conserved double stranded DNA and histone binding protein. Interactions between LEM-D proteins and BAF target nuclear membranes to chromosomes during nuclear assembly after mitosis. In addition, LEM-D proteins interact with BAF to tether the genome to the nuclear periphery and establish repressed chromatin domains in non-dividing cells. We investigate the Drosophila LEM-D family, focusing on Otefin, a LEM-D protein that is required for survival of adult germline stem cells (GSCs). The otefin mutant GSCs carry structural deformities of the NL and chromatin changes that are shared with laminopathic cells. My lab discovered that these mutant GSCs die because of activation of a novel checkpoint pathway that uses two DNA damage response (DDR) kinases, ATR and Checkpoint kinase 2 (Chk2). Although otefin mutant GSCs carry DNA damage, damage accumulation depends upon Chk2, demonstrating that DNA damage results from checkpoint activation. Based on these and other data, we hypothesize that NL deformation is responsible for activation of ATR and Chk2, a prediction supported by emerging evidence that ATR is a global sensor of structural deformities of cellular components. In this proposal, two Aims are proposed. In Aim 1, we will define the mechanism of ATR/Chk2 activation in otefin mutant GSCs. In Aim 2, we define Chk2- dependent pathways involved in GSC death. We expect our studies will have a broad impact. Nuclear shape changes are shared features of laminopathies and premature aging syndromes. We predict that activation of the NL checkpoint might contribute to lost stem cell maintenance in these diseases.

抽象的人椎板病是由编码核层（NL）的基因突变引起的蛋白质。这些蛋白质形成一个广泛的网络，位于内部核下方膜。一个统一的疾病模型表明，组织稳态丧失是由于无法维持成年干细胞。虽然NL蛋白负责椎板病已经确定了，尚不清楚这些蛋白如何维持健康的干细胞种群并促进组织稳态。 LEM域的保守NL家族（LEM-D）蛋白质在建立核结构和NL中起关键作用。 LEM-D 蛋白质结合屏障到自动的组合因子（BAF），保守的双链DNA 和组蛋白结合蛋白。 LEM-D蛋白与BAF目标之间的相互作用有丝分裂后核总成过程中核膜。此外， LEM-D蛋白与BAF相互作用，将基因组绑定到核外围，并在非分裂细胞中建立抑制染色质结构域。我们调查果蝇LEM-D家族，专注于Otefin，这是一种LEM-D蛋白，是必需的成人种系干细胞（GSC）的存活。 Otefin突变体GSC携带结构与椎板病细胞共享的NL和染色质变化的畸形。我的实验室发现，这些突变的GSC因激活新的检查点而死亡使用两个DNA损伤响应（DDR）激酶，ATR和检查点的途径激酶2（CHK2）。尽管otefin突变GSC遭受DNA损伤，但损害积累取决于CHK2，表明DNA损伤是由检查点激活。基于这些和其他数据，我们假设NL 变形负责ATR和CHK2的激活，这是由新兴的证据表明ATR是细胞结构畸形的全球传感器成分。在此提案中，提出了两个目标。在AIM 1中，我们将定义 otefin突变体GSC中ATR/CHK2激活的机理。在AIM 2中，我们定义CHK2-- 涉及GSC死亡的依赖途径。我们预计我们的学习将有一个广泛的影响。核形状变化是椎板病的共同特征和过早的特征衰老综合征。我们预测NL检查站的激活可能会导致丢失这些疾病中的干细胞维持。