Polarity Signals and MyosinII Coordinate Neuron Migration and Germinal Zone Exit

极性信号和肌球蛋白 II 协调神经元迁移和生发区退出

• 批准号: 8236545
• 负责人: David Joseph Solecki
• 金额: $ 38.28万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8236545
• 关键词: Actins; Actomyosin; Address; Adhesions; Binding; Biochemical; Bioinformatics; Biological Assay; Brain; Calmodulin; Cell Adhesion; Centrosome; Clinical; Cognition Disorders; Complex; Cytoplasmic Granules; Cytoskeletal Modeling; Cytoskeleton; Data; Development; Disease; Dynein ATPase; Ectopic Expression; Elements; Epilepsy; Equilibrium; Erinaceidae; Foundations; Gene Silencing; Genetic Models; Goals; Image; Immigration; Kinetics; Knowledge; Laboratories; Lead; Length; Life; Link; Malignant Childhood Neoplasm; Mental Retardation; Methods; Mitogens; Modeling; Molecular Motors; Morphogenesis; Motor; Movement; Myosin ATPase; Myosin Heavy Chains; Myosin Light Chain Kinase; Myosin Light Chains; Myosin Type I; Myosin Type II; Neurites; Neurons; Nonmuscle Myosin Type IIB; Organelles; Phenotype; Phosphorylation; Positioning Attribute; Preparation; Process; Protein Binding; Radial; Regulation; Signal Transduction; Signaling Molecule; Signaling Protein; Site; Slice; Testing; Time; Uncertainty; adhesion process; base; cell motility; cellular imaging; developmental disease; imaging probe; insight; interest; loss of function; migration; mutant; neuronal circuitry; novel; prevent; progenitor; programs; scaffold; smoothened signaling pathway; time use

DESCRIPTION (provided by applicant): Neuronal migration is essential for the morphogenesis of the developing brain, and defective migration or germinal zone (GZ) exit contributes to profound developmental and cognitive disorders, such as mental retardation, epilepsy and pediatric cancer [1-4]. Despite recent advances implicating the cytoskeleton as a critical regulator of neuronal motility [5, 6], a key remaining challenge is to understand how disparate elements (substrate adhesions, cytoskeletal components and signaling molecules) are coordinated to cooperatively execute complex neuronal motility programs, such as nucleokinesis or GZ exit. Studies in my laboratory using the cerebellar granule neuron (CGN) model illustrate that signaling through the partitioning defective (PAR) polarity complex regulates multiple aspects of neuronal motility, including radial migration initiation, neuronal adhesion to migration substrates, the cadence of nucleokinesis (i.e., centrosomal and somal motility) and a potential functional interaction between the PAR complex and Myosin II, a molecular motor that is essential for nucleokinesis [7-9]; however, the upstream regulators and downstream effectors of the PAR during these processes are currently unclear. The long-term goal of this proposal is to characterize upstream regulators and downstream effector(s) of the PAR complex critical for migration to elucidate how cytoskeletal organization, adhesion dynamics and migration initiation are globally coordinated during brain development. We will use gain- and loss-of-function approaches in combination with advanced live cell imaging in ex vivo cerebellar slice preparations to test three hypotheses related to our long term goal: I. Myosin II, an actin-based motor, powers polarized organelle motility and leading-process adhesion dynamics during nucleokinesis. II. The PAR complex regulates myosin II motors to orchestrate cytoskeletal and adhesion dynamics required for nucleokinesis. III. A competitive balance between Shh signaling and Par6 regulates CGN GZ exit and radial migration initiation through JAM-C adhesion. We propose three Aims to address each of these hypotheses: Aim 1: Determine whether leading process Myosin II motors are necessary for centrosomal and somal motility and leading process adhesion dynamics during radial migration. Aim 2: Demonstrate that Par6 regulates Myosin II activity and JAM-C adhesions by scaffolding actomyosin components via an IQ motif. Aim3: Determine whether excess Shh activity in Patched heterozygous CGNs regulates Par6 dependant GZ exit and JAM-C adhesion. At the end of this study, we will create a new conceptual framework for an integrated model of neuronal motility and provide novel insight into the pathological mechanisms of neuronal positioning disorders and pediatric cancer. PUBLIC HEALTH RELEVANCE: Proper regulation of neuronal positioning directs the formation of the neuronal laminae that are the foundation of neuronal circuitry. Errors in migration lead to developmental abnormalities that are the basis of diseases like mental retardation, epilepsy and pediatric cancer. The goal of this proposal is to understand the function of key signaling proteins and molecular motors, which are promising targets to understand the forces that power the migration of neurons in the developing brain, information that will be essential to eventually prevent or treat neuronal positioning disorders.

描述（由申请人提供）：神经元迁移对于发育中的大脑的形态发生至关重要，有缺陷的迁移或生发区（GZ）退出有助于深刻的发育和认知障碍，例如智力低下，癫痫，癫痫和小儿癌[1-4]。尽管最近的进步将细胞骨架作为神经元运动的关键调节剂[5，6]，但剩余的关键挑战是了解如何将元素（底物粘附，细胞骨架成分和信号分子）均可共同执行复杂的神经神经元运动程序，例如核蛋白或核糖exit。使用小脑颗粒神经元（CGN）模型在我的实验室中进行的研究表明，通过分配有缺陷（PAR）极性复合物的信号调节神经元运动的多个方面，包括径向迁移的起始，神经元的粘附，迁移到迁移的迁移，核定型和核定的序列（即，核定序列）的动力（即，一个核定型的序列）（即，均具有动力）。 ii，一种对核代动物必不可少的分子运动[7-9]；但是，目前尚不清楚PAR期间PAR的上游调节器和下游效应子。该提案的长期目标是表征PAR复合物的上游调节剂和下游效应子的迁移至关重要的，以阐明在大脑发育过程中的细胞骨架组织，粘附动力学和迁移启动如何在全球范围内进行全球协调。我们将使用功能丧失方法与离体小脑切片制剂中的先进的活细胞成像结合使用，以测试与我们的长期目标相关的三个假设：I.肌球蛋白II，基于肌动蛋白的电动机，极化细胞器的细胞器运动性和领先的核酸盐粘附动力学。 ii。 PAR复合物调节肌球蛋白II电动机来编排细胞骨架和核子所需的粘附动力学。 iii。 SHH信号和PAR6之间的竞争平衡可通过JAM-C粘附来调节CGN GZ出口和径向迁移启动。我们提出了三个目的，旨在解决这些假设中的每一个：目标1：确定肌球蛋白II电动机在径向迁移过程中是否需要进行肌球蛋白II电动机以及中心运动和领先的过程粘附动力学。 AIM 2：证明PAR6通过通过智商基序脚手架肌球蛋白成分来调节肌球蛋白II活性和JAM-C粘附。 AIM3：确定修补的杂合CGN中过量的SHH活性是否调节PAR6依赖性GZ出口和JAM-C粘附。在这项研究结束时，我们将为神经元运动的综合模型创建一个新的概念框架，并为神经元定位障碍和小儿癌的病理机制提供新的见解。 公共卫生相关性：对神经元定位的适当调节指导神经元层的形成，这是神经元电路的基础。迁移错误导致发育异常，这些异常是诸如智力低下，癫痫和小儿癌等疾病的基础。该提案的目的是了解关键信号蛋白和分子电机的功能，这是有望了解开发神经元在发育中的大脑中迁移的力的目标，这对于最终预防或治疗神经元定位障碍至关重要。