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.

抽象的人类核纤层病是由编码核纤层 (NL) 的基因突变引起的蛋白质。这些蛋白质形成了位于内核下方的广泛网络膜。统一的疾病模型表明，组织稳态的丧失是由于无法维持成体干细胞。尽管 NL 蛋白导致核纤层蛋白病已被鉴定，但仍不清楚这些蛋白质如何维持健康的干细胞群体并促进组织稳态。 LEM 结构域的保守 NL 家族 (LEM-D) 蛋白在构建核结构和 NL 中发挥着关键作用。 LEM-D 蛋白质结合屏障自动整合因子 (BAF)，这是一种保守的双链 DNA 和组蛋白结合蛋白。 LEM-D 蛋白与 BAF 靶标之间的相互作用有丝分裂后核组装过程中核膜与染色体的结合。此外， LEM-D 蛋白与 BAF 相互作用，将基因组束缚在核外围，在非分裂细胞中建立抑制的染色质结构域。我们调查了果蝇 LEM-D 家族，重点关注 Otefin，这是一种 LEM-D 蛋白，是成体生殖干细胞 (GSC) 的存活。 otefin 突变体 GSC 携带结构 NL 畸形和核纤层蛋白病细胞共有的染色质变化。我的实验室发现这些突变的 GSC 因新检查点的激活而死亡使用两种 DNA 损伤反应 (DDR) 激酶 ATR 和检查点的途径激酶 2 (Chk2)。尽管otefin突变体GSC携带DNA损伤，但损伤积累取决于 Chk2，证明 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，这一预测支持新的证据表明 ATR 是细胞结构畸形的全局传感器成分。在该提案中，提出了两个目标。在目标 1 中，我们将定义 otefin 突变 GSC 中 ATR/Chk2 激活机制。在目标 2 中，我们定义 Chk2- 参与 GSC 死亡的依赖途径。我们期望我们的研究将具有广泛的影响。核形状变化是核纤层蛋白病和早产儿的共同特征衰老综合症。我们预测 NL 检查点的激活可能会导致丢失这些疾病中的干细胞维持。