Clustering Postsynaptic Proteins at Neuromuscular Synapses: From Dok-7 to Rapsyn

神经肌肉突触处的突触后蛋白聚集：从 Dok-7 到 Rapsyn

基本信息

批准号：
8461165
负责人：
Steven Burden
金额：
$ 40.77万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-07-15 至 2016-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8461165
关键词：
Adult Agrin Binding Biochemical Biochemical Genetics Birth Cells Cholinergic Receptors Complex Congenital Myasthenic Syndromes Cytoskeleton Data Defect Disease Failure Genes Genetic Health Human Integral Membrane Protein Intercellular Junctions Lead Ligands Link Maintenance Mass Spectrum Analysis Mediating Membrane Proteins Motor Neurons Movement Mus Muscle Fatigue Muscle Fibers Muscle Weakness Muscle-Specific Kinase Mutation Myasthenia Nerve Neurodegenerative Disorders Neuromuscular Diseases Neurotransmitter Receptor PTB Domain Pathway interactions Peripheral Phosphorylation Play Postsynaptic Membrane Procedures Protein Binding Proteins Recruitment Activity Role SH3 Domains Signal Pathway Signal Transduction Skeletal Muscle Synapses Synaptic Transmission Tyrosine Tyrosine Phosphorylation Work adapter protein agrin receptor clinically relevant congenital neuromuscular disorder design mutant neuromuscular novel therapeutics peripheral membrane protein 43K postsynaptic programs protein complex protein function research study scaffold src Homology Region 2 Domain synaptogenesis

项目摘要

The Agrin/Lrp4/MuSK/Dok-7 signal transduction cascade is critical for synaptogenesis. Binding between Agrin and Lrp4 stimulates tyrosine phosphorylation of MuSK and recruitment and tyrosine phosphorylation of Dok-7. Hypomorphic mutations in human Agrin, MuSK or Dok-7, which impair their function, cause congenital myasthenia, characterized by structurally and functionally defective synapses, leading to muscle weakness and fatigue, emphasizing the clinical relevance of this signaling pathway. Once phosphorylated, Dok-7 recruits Crk and Crk-L, two related adapter proteins. The Agrin/Lrp4/Dok-7/Crk/Crk-L signaling pathway ultimately intersects with the cytoskeleton to cause accumulation of AChRs and other proteins in the postsynaptic membrane. The experiments in this proposal are designed to reveal the molecules and mechanisms that link recruitment of Crk/Crk-L to the redistribution and anchoring of acetylcholine receptors (AChRs) at developing and adult synapses. The proposed experiments will identify proteins that associate with Rapsyn, an AChR-associated protein that is essential to cluster AChRs, and analyze how these newly identified synaptic proteins, including Vezatin, regulate synaptic differentiation. These studies are clinically relevant, as mutations in Agrin, MuSK, Dok-7 and Rapsyn cause congenital myasthenia, so understanding how these proteins work will contribute to a better understanding of these diseases and may lead to novel therapeutic strategies. Moreover, mutations in genes that are downstream from Crk/Crk-L may likewise cause congenital myasthenia, so identifying the pathway downstream from Crk/Crk-L may reveal new genes responsible for congenital myasthenia.

Agrin/Lrp4/MuSK/Dok-7 信号转导级联对于突触发生至关重要。 Agrin 和 Lrp4 之间的结合刺激 MuSK 的酪氨酸磷酸化以及 Dok-7 的募集和酪氨酸磷酸化。人类 Agrin、MuSK 或 Dok-7 的亚等位突变会损害其功能，导致先天性肌无力，其特征是突触结构和功能缺陷，导致肌肉无力和疲劳，强调了该信号通路的临床相关性。一旦磷酸化，Dok-7 就会招募 Crk 和 Crk-L 这两种相关的衔接蛋白。 Agrin/Lrp4/Dok-7/Crk/Crk-L 信号通路最终与细胞骨架相交，导致 AChR 和其他蛋白质在突触后膜中积累。本提案中的实验旨在揭示将 Crk/Crk-L 募集与发育中和成体突触处乙酰胆碱受体 (AChR) 重新分布和锚定联系起来的分子和机制。拟议的实验将鉴定与 Rapsyn（一种 AChR 相关蛋白，对于 AChR 聚类至关重要）相关的蛋白质，并分析这些新鉴定的突触蛋白（包括 Vezatin）如何调节突触分化。这些研究具有临床意义，因为 Agrin、MuSK、Dok-7 和 Rapsyn 的突变会导致先天性肌无力，因此了解这些蛋白质的工作原理将有助于更好地了解这些疾病，并可能带来新的治疗策略。此外，Crk/Crk-L下游基因的突变同样可能导致先天性肌无力，因此识别Crk/Crk-L下游的通路可能会揭示导致先天性肌无力的新基因。