Interplay between tau and PKA condensates in ADRD

ADRD 中 tau 蛋白和 PKA 缩合物之间的相互作用

• 批准号: 10584358
• 负责人: STEFAN STRACK
• 金额: $ 24.86万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10584358
• 关键词: Acceleration; Adult; Age; Age Months; Aging; Alleles; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease related dementia; Antibodies; Binding; Biochemical; Biochemistry; Biological Assay; Biosensor; Brain; Buffers; CREB1 gene; Cells; Child; Cognitive; Collaborations; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Data; Dementia; Development; Disease; Epitopes; Fluorescence Recovery After Photobleaching; Frontotemporal Dementia; Genes; Genetic Transcription; Heterozygote; Human; Image; Immunofluorescence Immunologic; Impaired cognition; Institution; Intellectual functioning disability; Label; Learning; Link; Liquid substance; Mediating; Memory; Memory Loss; Memory impairment; Microtubules; Modeling; Molecular; Motor; Mus; Mutant Strains Mice; Mutation; Neuroglia; Neurologic Symptoms; Neurons; Pathogenicity; Pathology; Pharmaceutical Preparations; Phase; Phosphodiesterase Inhibitors; Physical condensation; Property; Protein Kinase; Protein Subunits; Proteins; Reporting; Resolution; Role; Signal Pathway; Signal Transduction; Specificity; Synaptic plasticity; Tauopathies; Testing; Therapeutic; Treatment Efficacy; age related; amyloid formation; biophysical techniques; cell type; clinical development; imaging approach; improved; in vivo; live cell imaging; mosaic; motor learning; mouse model; mutant; new therapeutic target; novel; prevent; protein degradation; spatial memory; tau Proteins; tau aggregation; tau-1; tau-protein kinase; therapy development; tool

Project Summary / Abstract Signaling by cAMP-dependent protein kinase (PKA) is essential for learning and memory and cAMP-elevating phosphodiesterase (PDE) inhibitors are in clinical development for Alzheimer’s disease (AD) and AD-related dementias (ADRD). RIβ is a brain-specific regulatory subunit of PKA and several RIβ mutations, among them. R335W and L50R, have recently been shown to cause neurological symptoms, including intellectual disability in children and dementia in adults. We recently discovered that RIα, the other RI regulatory subunit of PKA, undergoes liquid-liquid phase separation (LLPS) as a function of cAMP signaling to dynamically buffer cAMP, which is critical for the specificity of the signaling pathway. In our preliminary studies, we showed that cAMP- bound RIβ also undergoes LLPS and the L50R and R335W mutations significantly alter the properties of RIβ condensates. Importantly, PKA is also involved in regulating tau condensates, as phosphorylation of tau by a suite of protein kinases including PKA has been shown to trigger tau LLPS. In addition, specific PKA signaling is critical for CREB mediated transcription and protein degradation, dysregulation of which contribute to AD/ADRD. However, the functional impact of RIβ condensates in AD/ADRD and the interplay between tau and RIβ condensates have not been explored. We assembled a multi-PI team with complementary expertise from two institutions to investigate the molecular and cellular mechanisms governing PKA/RIβ phase-separation and protection from tauopathy and cognitive decline during aging and in disease. To this end, we generated mice carrying epitope-tagged wild-type and pathogenic R335W and L50R alleles of Prkar1b, the gene encoding RIβ. We hypothesize that defective RIβ LLPS and dysregulated interplays between RIβ and tau condensates are critically linked to AD/ADRD. In aim 1, we will use multiple cell types, including cortical cultures from Prkar1b-mutant mice to study the interplay between tau and RIβ condensates using biophysical and imaging approaches. Aim 2 seeks to answer the complementary question how the two phase-separating proteins interact functionally in vivo to influence tau pathology and memory loss in a mouse model of frontotemporal dementia (hTau P301L). Our proposed study will not only develop novel tools and mouse models to study the impact of defective RIβ LLPS and interplays between RIβ and tau condensates, but also establish a collaboration framework for further mechanistic studies of dysregulated biomolecular condensates in AD/ADRD. A better understanding of underlying mechanisms is paramount to identify new therapeutic targets and to improve upon the efficacy of therapeutics under development, such as PDE inhibitors.

项目摘要 /摘要 依赖cAMP蛋白激酶（PKA）的信号对于学习和记忆和营地至关重要 磷酸二酯酶（PDE）抑制剂正在阿尔茨海默氏病（AD）和AD相关的临床发育中 痴呆症（ADRD）。 RIβ是PKA的大脑特异性调节亚基，其中包括几种RIβ突变。 R335W和L50R最近被证明会引起神经系统症状，包括智力障碍 在儿童和成人的痴呆症中。我们最近发现，PKA的另一个RI调节亚基Riα， 经历液态液相分离（LLP），这是cAMP信号的函数，动态缓冲室， 在我们的初步研究中，我们表明营地 - 结合的RIβ还经历了LLP，L50R和R335W突变显着改变了Riβ的特性 冷凝水。重要的是，PKA还参与调节tau冷凝物，作为tau的磷酸化 包括PKA在内的蛋白激酶套件已显示出触发tau llps。另外，特定的PKA信号传导 对于CREB介导的转录和蛋白质降解至关重要，其失调有助于 广告/adrd。但是，RIβ凝结物在AD/ADRD中的功能影响以及Tau和Tau之间的相互作用 尚未探索RIβ冷凝物。 我们组装了一个具有来自两个机构的完善专业知识来研究分子的团队 以及控制PKA/RIβ相分离的细胞机制，并保护tauopathy和Cognitive 衰老和疾病期间的下降。为此，我们产生了携带表位标记的野生型的小鼠， Prkar1b的致病R335W和L50R等位基因，编码Riβ的基因。我们假设RIβ有缺陷 LLP和RIβ和TAU冷凝水之间的相互作用与AD/ADRD密切相关。目标 1，我们将使用多种细胞类型，包括来自Prkar1b突变小鼠的皮质培养物来研究相互作用 使用生物物理和成像方法之间的tau和Riβ凝结。 AIM 2试图回答 完全质疑两种分离蛋白如何在体内功能上相互作用以影响tau 额颞痴呆的小鼠模型（HTAU P301L）中的病理和记忆力丧失。我们提出的研究 不仅会开发新的工具和小鼠模型来研究有缺陷的RIβLLP和相互作用的影响 在RIβ和TAU凝结之间，但也为进一步的机械研究建立了协作框架 AD/ADRD中的生物分子冷凝物的失调。更好地了解基本机制是 至关重要的是确定新的治疗靶点并提高治疗效率 开发，例如PDE抑制剂。