Modulation of RhoA Signaling by the mRNA Binding Protein hnRNPQ1

mRNA 结合蛋白 hnRNPQ1 对 RhoA 信号传导的调节

• 批准号: 8458758
• 负责人: Kathryn Renae Moss
• 金额: $ 3.09万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8458758
• 关键词: Actins; Affect; Autistic Disorder; Axon; Binding Proteins; Biological Assay; Biology; Biotin; Brain; Cell Line; Cells; Communication; Couples; Cultured Cells; Cytoplasmic Granules; Dendrites; Dendritic Spines; Development; Disease; Down-Regulation; Excitatory Synapse; Fluorescent in Situ Hybridization; Gene Expression; Genetic Translation; Goals; Growth; Hippocampus (Brain); Immunofluorescence Immunologic; Immunoprecipitation; In Vitro; Intellectual functioning disability; Investigation; Knowledge; Label; Lead; Learning; Link; Luciferases; Maintenance; Mediating; Memory; Messenger RNA; Molecular; Monomeric GTP-Binding Proteins; Morphogenesis; Morphology; Myoblasts; Natural regeneration; Neurons; Phenotype; Play; Protein Biosynthesis; RNA; Recombinants; Regulation; Reporter; Research; Role; Shapes; Signal Pathway; Signal Transduction; Site; Small Interfering RNA; Structure; Synapses; Tertiary Protein Structure; Translations; Untranslated Regions; Vertebral column; autism spectrum disorder; base; crosslink; density; improved; in vivo; inhibitor/antagonist; insight; messenger ribonucleoprotein; molecular phenotype; nerve supply; nervous system disorder; neuron development; neuropsychiatry; novel; novel therapeutics; protein function; research study; response; rhoA GTP-Binding Protein

DESCRIPTION (provided by applicant): Abnormal neuronal morphology is a common theme among intellectual disabilities and autism despite the diverse pathological mechanisms underlying these disorders. Specifically, numerous neuropsychiatric diseases have been demonstrated to present with abnormalities in the morphology of dendritic spines, small actin-rich compartments that protrude from the dendrites. The small GTPase, RhoA, a well-characterized regulator of actin dynamics, has been suggested to play a critical role in regulating the morphology of these actin-rich spines. Our lab has revealed that the mRNA binding protein hnRNPQ1 interacts with RhoA mRNA and downregulation of hnRNPQ1 increases steady state RhoA protein levels without increasing RhoA mRNA levels in cultured cells. Additionally, depletion of hnRNPQ1 causes phenotypes associated with increased RhoA signaling in cultured cell lines and primary neuronal cultures. Furthermore, the reduction in hippocampal neuron dendritic spine density observed upon hnRNPQ1 depletion can be rescued by pharmacological inhibition of the RhoA signaling pathway. These preliminary studies warrant investigation of the possible role of hnRNPQ1 in mediating RhoA protein synthesis and signaling in primary neuronal cultures. The proposed research aims to characterize the interaction between hnRNPQ1 protein and RhoA mRNA (Specific Aim 1) and determine whether hnRNPQ1 regulates RhoA mRNA translation locally in dendrites (Specific Aim 2). Additionally, the role of hnRNPQ1 in regulating dendritic spine morphology and RhoA signaling will be assessed in primary neuronal cultures by depleting hnRNPQ1 and analyzing dendritic spine morphological and molecular phenotypes (Specific Aim 3). We hypothesize that hnRNPQ1 negatively regulates the local translation of RhoA mRNA in dendrites, therefore modulating dendritic spine morphology through altered RhoA signaling. This study attempts to link RhoA expression regulation to RhoA signaling modulation and consequently synaptic development, maintenance and plasticity, which is currently a critical gap in our knowledge. Studying the mechanisms involved in regulating dendritic spine morphogenesis will improve our understanding of intellectual disabilities and autism, which will aid in the development of new treatments for these disorders.

描述（由申请人提供）：尽管这些疾病的病理机制多种多样，但神经元形态异常是智力障碍和自闭症的共同主题。具体来说，许多神经精神疾病已被证明表现为树突棘形态异常，即从树突突出的富含肌动蛋白的小室。小 GTP 酶 RhoA 是一种特征明确的肌动蛋白动力学调节因子，已被认为在调节这些富含肌动蛋白的棘的形态方面发挥着关键作用。我们的实验室发现，mRNA 结合蛋白 hnRNPQ1 与 RhoA mRNA 相互作用，并且 hnRNPQ1 的下调会增加稳态 RhoA 蛋白水平，而不会增加培养细胞中的 RhoA mRNA 水平。此外，hnRNPQ1 的消耗会导致与培养细胞系和原代神经元培养物中 RhoA 信号传导增加相关的表型。此外，在 hnRNPQ1 耗尽时观察到的海马神经元树突棘密度的降低可以通过药物抑制 RhoA 信号通路来挽救。这些初步研究有必要调查 hnRNPQ1 在介导原代神经元培养物中 RhoA 蛋白合成和信号传导中的可能作用。拟议的研究旨在表征 hnRNPQ1 蛋白和 RhoA mRNA 之间的相互作用（具体目标 1），并确定 hnRNPQ1 是否在树突中局部调节 RhoA mRNA 翻译（具体目标 2）。此外，将通过耗尽 hnRNPQ1 并分析树突棘形态和分子表型，在原代神经元培养物中评估 hnRNPQ1 在调节树突棘形态和 RhoA 信号传导中的作用（具体目标 3）。我们假设 hnRNPQ1 负向调节树突中 RhoA mRNA 的局部翻译，因此通过改变 RhoA 信号传导来调节树突棘形态。这项研究试图将 RhoA 表达调控与 RhoA 信号调节以及突触发育、维持和可塑性联系起来，这是目前我们知识中的一个关键空白。研究调节树突棘形态发生的机制将提高我们对智力障碍和自闭症的理解，这将有助于开发针对这些疾病的新疗法。