A phospho-switch in delta-catenin: relationship to PDZ-domain proteins and neuron development

δ-连环蛋白中的磷酸开关：与 PDZ 结构域蛋白和神经元发育的关系

• 批准号: 10170431
• 负责人: PIERRE D MCCREA
• 金额: $ 43.82万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10170431
• 关键词: Actins; Address; Armadillo Repeat; Back; Binding; Biochemical; Brain; C-terminal; Cadherins; Cell Adhesion; Cell Adhesion Molecules; Cells; Cellular Structures; Cognition Disorders; Complex; Cri-du-Chat Syndrome; Cytoskeleton; Dendrites; Dendritic Spines; Dependence; Development; Disease; Evaluation; Exhibits; Family; Felis catus; Functional disorder; Generations; Goals; Growth Cones; Hippocampus (Brain); Homeostasis; Lead; Ligand Binding; Ligands; Mediator of activation protein; Molecular; Monomeric GTP-Binding Proteins; Morphogenesis; Morphology; Neurodevelopmental Disorder; Neurons; Outcome; Output; Pathology; Pathway interactions; Pattern; Phosphorylation; Phosphorylation Site; Process; Proteins; Rattus; Receptor Signaling; Role; Schizophrenia; Structure; Synapses; System; Tertiary Protein Structure; Work; autism spectrum disorder; base; delta-catenin; experience; experimental study; innovation; insight; knock-down; member; membrane-associated guanylate kinase; nervous system disorder; neurite growth; neurodevelopment; neuron development; neuronal cell body; neuronal circuitry; novel; protein complex; relating to nervous system; scaffold; synaptogenesis; upstream kinase

PROJECT SUMMARY/ABSTRACT Generation of neuronal connectivity is regulated during brain development, with the formation of synapses being dependent on the morphology of dendrites, branch-like structures extending out from neurons. Disruptions in dendrite formation can thus lead to atypical synaptic connectivity, associated with neurodevelopmental disorders such as autism, schizophrenia and Cri-du-chat syndrome. Our proposal seeks to better understand molecular processes underlying the morphology of dendrites. This will occur through examination of two novel protein complexes we recently revealed, each involving delta-catenin. delta-Catenin belongs the p120-subfamily of catenin proteins, whose members have are best known for their functions in association with cadherin cell-adhesion proteins and cytoskeletal-associated partners including small- GTPases. delta-Catenin localizes to neuronal dendrites and synapses where it functions in development and homeostasis. Delta-catenin possesses a central armadillo-repeat domain present in most catenins, but it additionally contains a PDZ-binding ligand at its extreme C-terminus. This PDZ-ligand binds to a number of PDZ-domain proteins crucial for synaptic and dendritic functions. Our preliminary findings have revealed two novel interactions between delta-catenin's PDZ-ligand and the PDZ-domain proteins Magi1 and Pdlim5. Magi1 is a member of the membrane-associated guanylate kinase (MAGUK) family that is expressed along dendrites with enrichment within the tips at early stages, potentially relevant to a role in dendrite extension. Pdlim5 is a PDZ-LIM protein also found in dendrites, but is believed to negatively regulate the neurite growth cone to halt the dendrite's lengthening. Our preliminary work using rat hippocampal neurons suggests that Magi1 expression promotes the lengthening of dendrites, while Pdlim5 appears instead to enhance branching. This presents us with the intriguing thought that two proteins with seemingly opposing roles can each bind delta- catenin. Analysis of these interactions has revealed a critical phosphorylation site in delta-catenin's PDZ-ligand that appears to determine which of the two interactions occurs, potentially contributing to the spatial and temporal control of dendritic morphologies. Using primary rat hippocampal neurons as well as HEK293 cells, the experiments proposed in this application examine the phospho-dependency (Aim 1) and the cellular and developmental significance of the delta-catenin:Magi1 and delta-catenin:Pdlim5 complexes (Aim 2). Experimental approaches include (among others) the selective disruption of these two delta-catenin complexes using knock-down/ add-back strategies. Given that the dysfunction of each of the three proteins under study are implicated in neurologic diseases, addressing their interactions and contributions to dendrite development could provide insight to the progression of neurodevelopmental disorders.

项目摘要/摘要 神经元连通性的产生在大脑发育过程中受到调节，并形成突触 取决于树突的形态，分支样结构从神经元中延伸。 因此，树突形成的破坏会导致非典型突触连通性，与 神经发育障碍，例如自闭症，精神分裂症和CRI-DU-CHAT综合征。我们的建议寻求 更好地了解树突形态的基础分子过程。这将通过 我们最近揭示的两种新型蛋白质复合物的检查，每种蛋白质复合物，每种均涉及三角洲-Catenin。 Delta-catenin 属于catenin蛋白的P120-子家族，其成员以其功能而闻名 与钙粘蛋白细胞粘附蛋白和细胞骨架相关伴侣的关联 GTPases。三角洲 - 钙蛋白本地化于神经元树突和突触，在发育中起作用， 稳态。 Delta-catenin在大多数catenin中都有一个中央武装舰重复域，但 另外，在其极端的C末端中包含PDZ结合配体。此PDZ-rigand结合了许多 PDZ结构域蛋白对于突触和树突功能至关重要。我们的初步发现揭示了两个 Delta-catenin的PDZ-配合与PDZ域蛋白Magi1和Pdlim5之间的新型相互作用。 Magi1 是沿树突表达的膜相关鸟苷酸酯激酶（MAGUK）家族的成员 在早期的尖端中富集，可能与树突扩展中的角色有关。 pdlim5是一个 在树突中也发现了PDZ-LIM蛋白 树突的延长。我们使用大鼠海马神经元的初步工作表明Magi1 表达促进了树突的延长，而PDLIM5似乎增强了分支。这 向我们展示了一种有趣的想法，即两个具有相反角色的蛋白质都可以绑定三角洲 catenin。对这些相互作用的分析揭示了Delta-catenin的PDZ-配合中的关键磷酸化位点 这似乎确定了两种相互作用中的哪些发生，有可能导致空间和 树突形态的时间控制。使用原发性大鼠海马神经元以及HEK293细胞， 本应用中提出的实验检查了磷酸依赖性（AIM 1）以及细胞和 三角洲 - 卡宁蛋白的发育意义：magi1和delta-catenin：pdlim5综合体（AIM 2）。 实验方法包括（除其他）这两种三角洲-Catenin复合物的选择性中断 使用敲门/添加策略。鉴于研究的三种蛋白质中每种功能障碍 与神经系统疾病有关，解决它们的相互作用和对树突发展的贡献 可以为神经发育障碍的进展提供见识。