Molecular mechanisms of C9orf72 and Matrin 3 interaction in ALS

ALS 中 C9orf72 和 Matrin 3 相互作用的分子机制

• 批准号: 9324387
• 负责人: Christopher James Donnelly
• 金额: $ 23.23万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9324387
• 关键词: 9p21; ALS patients; Alternative Splicing; Amyotrophic Lateral Sclerosis; Animal Model; Architecture; Binding; Binding Proteins; Biochemical; Biochemical Genetics; Biological; Biological Assay; Biological Models; C9ORF72; Cell Culture Techniques; Cell model; Cells; Chromosomes; Cytoplasmic Inclusion; Data; Dipeptides; Disease; Drosophila genus; Ectopic Expression; Exons; Frontotemporal Dementia; Genes; Genetic; Genetic Transcription; Human; Impairment; Lamin Type A; Lamin Type B; Link; Mammalian Cell; Mediating; Membrane; Microscopy; Modeling; Molecular; Motor Cortex; Motor Neurons; Mutation; Nerve Degeneration; Neurons; Nuclear; Nuclear Envelope; Nuclear Matrix; Nuclear Matrix-Associated Proteins; Nuclear RNA; Pathogenesis; Pathogenicity; Pathologic; Patients; Peptides; Phenotype; Physiological; Process; Production; Proteins; RNA; RNA Binding; RNA Recognition Motif; RNA-Binding Proteins; Role; Spinal Cord; Testing; Tissues; Toxic effect; Transcript; Translating; Translations; Untranslated RNA; Variant; base; cell cortex; effective therapy; fly; frontotemporal lobar dementia-amyotrophic lateral sclerosis; genetic approach; in vivo; in vivo Model; induced pluripotent stem cell; insight; matrin 3; mutant; neurodegenerative phenotype; novel; nucleocytoplasmic transport; protein TDP-43; protein transport; time use; trafficking

Abstract GGGGCC hexanucleotide repeat expansions (G4C2), in the non-coding region of the C9orf72 gene on chromosome 9p21, are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia. G4C2 expansions in C9orf72 cause a loss of nuclear membrane integrity which in turn leads to mislocalization of nuclear TDP-43 (another ALS causing protein) in the spinal cords of C9 ALS patients. Recently, expanded hexanucleotide repeat binding proteins have been identified in neurons differentiated from induced pluripotent stem cells and motor cortex tissue from C9-ALS patients. Matrin-3 (MATR3) interacts with hexanucleotide repeats in two independent studies. Mutations in MATR3, an RNA binding nuclear matrix protein, are a known genetic cause of ALS. MATR3 interacts with nuclear matrix proteins such as Lamin A suggesting potential role of MATR3 in regulating nuclear matrix architecture and function. MATR3 positive cytoplasmic inclusions have been identified in an ALS patient known to carry the C9orf72 repeat expansion suggesting a potential link between these two forms of ALS. MATR3 binds to the G4C2 in C9orf72 and the binding motif recognized by MATR3 has been found to be enriched in sporadic ALS patients’ alternative splicing cassette exons. However, the physiological consequences of the interaction between MATR3 and expanded G4C2 repeats, as well as the relevance of this interaction to ALS pathogenesis, are not yet known. We found that ectopic expression of wild type (WT) MATR3 strongly suppresses neurodegenerative phenotype in a Drosophila model of mutant C9ORF72 hexanucleotide repeat expansions (HNE). We observed that ablating the RNA binding domain in WT-MATR3 blocks its ability to suppress C9-HNE toxicity in vivo, suggesting that the rescue phenotype depends on HNE RNA transcripts binding to WT-MATR3. Here, we propose to investigate this novel interaction between WT-MATR3 and C9ORF72-HNE and its impact on C9ORF72-HNE neurodegenerative phenotype. In this R21 proposal, we will thoroughly examine the relationship between MATR3 and C9 using biochemical, genetic and molecular approaches in mammalian cell cultures, induced pluripotent stem cells from C9 patients and Drosophila models of C9orf72-mediated neurodegeneration.

抽象的 GGGGCC六核苷酸重复膨胀（G4C2），在C9ORF72基因的非编码区域 9p21染色体是肌萎缩性侧索硬化和额颞痴呆的最常见原因。 C9ORF72中的G4C2扩展会导致核膜完整性丧失，这又导致倾位错误 C9 ALS患者的脊髓中的核TDP-43（另一个ALS引起蛋白质）最近，扩展了 六核苷酸重复结合蛋白已在与诱导多能分化的神经元中鉴定 来自C9-ALS患者的干细胞和运动皮层组织。 Matrin-3（MATR3）与六核苷酸相互作用 在两项独立研究中重复。 MATR3中的突变是RNA结合核基质蛋白，是已知的 ALS的遗传原因。 MATR3与核基质蛋白（如层粘连蛋白A）相互作用表明潜在作用 MATR3在确定核基质体系结构和功能中的。 MATR3阳性细胞质夹杂物具有 在已知携带C9ORF72重复扩展的ALS患者中发现了潜在的链接 在这两种形式的ALS之间。 MATR3与C9ORF72中的G4C2结合，并结合了结合基序 已发现MATR3富含零星ALS患者的替代剪接盒式外显子。然而， MATR3和扩展的G4C2重复序列之间相互作用的物理后果，以及 这种相互作用与ALS发病机理的相关性尚不清楚。 我们发现野生型的生态表达（WT）MATR3强烈抑制神经退行性表型 在突变C9orf72六核苷酸重复膨胀（HNE）的果蝇模型中。我们观察到了 在WT-MAT​​R3中燃烧RNA结合结构域阻止其抑制体内C9-HNE毒性的能力， 表明救援表型取决于与WT-MAT​​R3结合的HNE RNA转录本。在这里，我们 提议调查WT-MAT​​R3和C9orf72-HNE之间的这种新型相互作用及其对 C9orf72-HNE神经退行性表型。在此R21提案中，我们将彻底检查 MATR3和C9使用哺乳动物细胞中的生化，遗传和分子方法之间的关系 培养物，来自C9患者的多能干细胞和C9orf72介导的果蝇模型 神经变性。