The COPA vesicle protein and pathogenesis of spinal muscular atrophy

COPA囊泡蛋白与脊髓性肌萎缩症发病机制

• 批准号: 8866202
• 负责人: ELLIOT J. ANDROPHY
• 金额: $ 34.08万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8866202
• 关键词: 3' Untranslated Regions; Address; Animal Model; Animals; Antibodies; Applications Grants; Axon; Axonal Transport; Binding; Biological; Carrier Proteins; Cell Culture Techniques; Cells; Coat Protein Complex I; Complex; Coupled; Data; Defect; Development; Endoplasmic Reticulum; Formaldehyde; Functional disorder; G-Quartets; Gene Expression Profile; Genetic; Genetic Transcription; Genetic study; Goals; Golgi Apparatus; Grant; Health; High-Throughput RNA Sequencing; Human; Infant Mortality; Intracellular Transport; Investigation; Longevity; Lysine; Maintenance; Mediating; Membrane Proteins; Messenger RNA; Modeling; Molecular; Motor; Motor Neuron Disease; Motor Neurons; Motor Skills; Mouse Strains; Mus; Muscle Weakness; Nature; Nerve Degeneration; Neurites; Neuromuscular Junction; Neuronal Dysfunction; Neurons; Nucleic Acids; Outcome; Pathogenesis; Pathology; Pathway interactions; Pattern; Physiological; Point Mutation; Process; Production; Protein Binding; Proteins; Publishing; RNA; RNA Splicing; Reporting; Resources; Role; Series; Spinal Muscular Atrophy; Subfamily lentivirinae; System; Techniques; Testing; Transgenic Mice; Transgenic Organisms; Transport Vesicles; Vesicle; base; crosslink; in vivo Model; innovation; insight; lysyllysine; motor disorder; motor neuron function; mouse model; neuron development; novel; research study; small hairpin RNA; trafficking

DESCRIPTION (provided by applicant): We discovered that the SMN protein binds to alpha-COP, the largest constituent of the heptameric COPI vesicle. The hypothesis to be investigated in this project is that pathogenesis of SMA results from inability of this cargo transport complex to sustain the functional integrity of motor neurons. We explore the role of the SMN protein's interaction with alpha-COP in neurite development and maintenance. Importantly, we observed that over-expression of alpha-COP restores neurite development in SMN depleted NSC34 cells. New data reveal that low levels of SMN alter the functionality of endoplasmic reticulum-Golgi trafficking, suggesting a previously unrecognized effect on this protein processing pathway. We recently reported that the alpha-COP complex incorporates ~800 specific RNAs from the total transcriptome of differentiated NSC-34 cells. A high fraction of these mRNAs contain in their 3' untranslated regions a G-quadruplex motif, which has been assigned a role in neurite localization. Our goal is to identify the mRNAs that depend on SMN for association with the COPI complex, enabling studies of the roles of alpha-COP and SMN in the trafficking of these RNAs into the axon and characterization of their requirement for neuronal development. To examine the biological physiologic significance of the interaction of SMN with alpha-COP and subsequent mechanistic studies, we generated novel transgenic mice with reduced levels of alpha-COP protein, with the prediction this will result in motor unit dysfunction. We also have created a transgenic strain that over-expresses tagged human alpha- COP. These mice will be crossed with SMA model mice with low levels of SMN to test the hypothesis that increased levels of alpha-COP and COPI vesicles promote SMN dependent cargo delivery to the axon and restore motor skills and increase lifespan. These experimental mouse models will be important resources to study the mechanism of neurodegeneration and the transport of proteins and specific RNAs to and within the axon. Pharmacologic induction of the COPI pathway may represent a novel means to treat SMA.

描述（由申请人提供）：我们发现SMN蛋白与Alpha-cop结合，Alpha-cop是七聚体copi囊泡的最大成分。该项目中要研究的假设是，SMA的发病机理是由于该货物传输复合物无法维持运动神经元的功能完整性而引起的。我们探讨了SMN蛋白与α-COP相互作用在神经突发育和维持中的作用。重要的是，我们观察到，α-COP的过表达恢复了SMN耗尽NSC34细胞中的神经突发育。新数据表明，较低水平的SMN改变了内质网的功能，这表明先前无法识别的对这种蛋白质加工途径的影响。我们最近报道说，α-Cop复合物在分化的NSC-34细胞的总转录组中结合了约800个特定的RNA。这些mRNA中的很大一部分包含在其3'未翻译区域中的G-四链体基序，该基序已在神经突定位中发挥作用。我们的目标是确定依赖SMN与COPI复合物相关的mRNA，从而可以研究α-COP和SMN在将这些RNA运输到轴突中的作用以及其神经元发育需求的表征。为了检查SMN与α-COP和随后的机械研究的相互作用的生物生理意义，我们产生了新型的转基因小鼠，其α-COP蛋白水平降低，并进行了预测，这将导致运动单位功能障碍。我们还创建了一个过表达标记的人αCop的转基因菌株。这些小鼠将与具有低水平的SMN的SMA模型小鼠交叉，以测试以下假设，即增加α-COP和COPI囊泡的水平可促进依赖SMN的货物递送到轴突并恢复运动技能并增加寿命。这些实验小鼠模型将是研究神经退行性机制以及蛋白质和特定RNA到轴突内部和内部的重要资源。 COPI途径的药理学诱导可能代表了治疗SMA的新型手段。