CRCNS: PKMzeta-Dependent Protein Synthesis Maintains Synaptic Plasticity

CRCNS：PKMzeta 依赖性蛋白质合成维持突触可塑性

• 批准号: 8444766
• 负责人: HAREL Zeev SHOUVAL
• 金额: $ 30.75万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8444766
• 关键词: Accounting; Address; Age; Back; Behavioral; Binding; Biochemical; Biological Sciences; Biology; Brain; Calcium; Calmodulin; Chemosensitization; Clinical; Collaborations; Communities; Computational Biology; Computer Simulation; Dependence; Diffuse; Diffusion; Disadvantaged; Drug abuse; Education; Feedback; Goals; Grant; Hippocampus (Brain); Hour; Housing; Human; In Vitro; Information Storage; Instruction; Kinetics; Knowledge; Learning; Life; Link; Long-Term Potentiation; Maintenance; Mediating; Memory; Mental disorders; Mentors; Messenger RNA; Methodology; Modeling; Molecular; Molecular Conformation; Neurons; Neurosciences; New York; Pathway interactions; Pharmaceutical Preparations; Phase; Phosphorylation; Phosphotransferases; Play; Post-Traumatic Stress Disorders; Property; Protein Biosynthesis; Protein Isoforms; Protein Kinase; Protein Kinase C; Protein Kinase M; Protein Synthesis Inhibitors; Proteins; Qualifying; Recording of previous events; Regulation; Research; Rice; Role; Science; Scientist; Simulate; Site; Slice; Solid; Solutions; Students; Synapses; Synaptic Transmission; Synaptic plasticity; System; Techniques; Testing; Theoretical model; Time; Toxic effect; Training; Translations; Work; Youth; abstracting; addiction; base; drug reward; drug seeking behavior; experience; high school; in vivo; inhibitor/antagonist; interest; long term memory; mathematical model; nervous system disorder; novel; outreach; painful neuropathy; programs; protein degradation; research study; response; simulation; theories

DESCRIPTION (provided by applicant): We all have memories that date back to our youth; we remember the house we lived in at age 4; we remember a favorite schoolteacher. The mechanism for storing these memories is believed to be the long-term plasticity of synaptic connections within specific neuronal circuits. However, this putative cellular basis of memory relies on proteins that typically have lifetimes far shorter than the memory. Here exactly lies a fundamental problem of long-term memory and synaptic plasticity: How can memories be stored for a human lifetime on the basis of proteins that are continuously degrading? Recently, it was shown that the brain-specific PKC isoform, protein kinase M??(PKM?), plays a unique role in maintaining both late long-term potentiation (L-LTP) of synapses and long-term memory. This crucial observation, however, does not explain how PKM??can overcome the natural degrading effect of protein turnover and diffusion. The central hypothesis of this proposal is that PKM??, through its control of its own synthesis, can form a bi-stable system, which can account for the maintenance of synapse specific long-term plasticity and memory. Here we propose to mathematically formulate this hypothesis within a biophysical model, and to analyze this model so as to propose testable experimental predictions. We then will directly test these predictions on PKM?-mediated persistent synaptic potentiation, using novel techniques tailored for testing the theory. Intellectual Merit: The finding that PKM??is both necessary and sufficient for the maintenance of synaptic plasticity and long-term memory has fundamentally changed the field of learning and memory, but much needs to be learned about the mechanisms that can actually accomplish the persistence of long-term plasticity and memory. This proposal addresses these questions using a combined theoretical and experimental approach. Such a theory in which bi-stability depends on regulation of translation is novel not only for neuroscience but also for biology in general. Our collaboration is uniquely qualified to carry out the proposed work because the Shouval lab has ample experience in modeling synaptic plasticity in collaboration with experimental groups, and the Sacktor lab has pioneered the science of PKM??and has ample experience with the proposed techniques. The experimental techniques include two new methodologies necessary for testing the predictions. First, we propose to test the model's predictions on protein translation in L-LTP, not by general protein synthesis inhibitors that may have issues of toxicity and indirect effects, but by use of antisense oligodeoxynucleotides directed to the translation start site of PKM??mRNA to specifically block PKM??synthesis in induction and maintenance. Second, because PKM?-mediated potentiation is both highly stable and yet rapidly reversible, we will use a fast-flow hippocampal slice chamber optimized for the study of the maintenance of L-LTP to test key predictions of the model. The proposed stochastic simulations of translation-dependent bi-stability are also novel in computational biology. Broader Impact: As the first demonstrated molecular mechanism of experience-dependent, long-term information storage in the brain, PKM??has significant clinical implications, and within the last year has been shown to contribute to in the biology of a variety of neurological and psychiatric diseases, including post-traumatic stress disorder, central neuropathic pain, and drug abuse. In order to assist the rapidly growing interest in PKM??in many labs, we will make our model accessible to the larger community, allowing for other scientists to test, modify, and incorporate their findings into the model, thus accelerating the pace of scientific discovery. Because an important goal for NSF is to integrate research and education, we will train a diverse pool of students. Our labs already train undergraduates, the Shouval lab takes undergraduates each summer through an REU program (PI S. Cox, Rice), and a UT system grant (PI H. Shouval), and local undergraduates throughout the year, and the Sacktor lab has had a long history of mentoring local disadvantaged high school students (e.g., through the Intel program). Both labs are dedicated to public outreach; for example, an article on PKM??and memory was on the front page of The New York Times. We are eager to extend this type of outreach to the domain of the interaction between theory and experiment in biological sciences.

描述（由申请人提供）：我们都有可以追溯到年轻时的记忆；我们记得我们四岁时住过的房子；我们记得一位最喜欢的老师。存储这些记忆的机制被认为是特定神经元回路内突触连接的长期可塑性。然而，这种假定的记忆细胞基础依赖于通常寿命比记忆短得多的蛋白质。这正是长期记忆和突触可塑性的一个基本问题：如何在不断降解的蛋白质的基础上存储人类一生的记忆？最近，研究表明，大脑特异性 PKC 亚型蛋白激酶 M??(PKM?) 在维持突触晚期长期增强 (L-LTP) 和长期记忆方面发挥着独特的作用。然而，这一重要的观察结果并不能解释 PKM 如何克服蛋白质周转和扩散的自然降解效应。该提议的中心假设是，PKM??通过控制自身的合成，可以形成双稳态系统，可以解释突触特异性长期可塑性和记忆的维持。在这里，我们建议在生物物理模型中以数学方式表述这一假设，并分析该模型以提出可检验的实验预测。然后，我们将使用为测试该理论而定制的新技术，直接测试对 PKM？介导的持续突触增强的这些预测。学术价值：PKM 对于维持突触可塑性和长期记忆来说既是必要也是充分的这一发现从根本上改变了学习和记忆领域，但对于真正能够实现长期可塑性和记忆持久性的机制还有很多需要了解。该提案采用理论和实验相结合的方法解决了这些问题。这种双稳定性取决于翻译调节的理论不仅对于神经科学而且对于一般生物学来说都是新颖的。我们的合作具有独特的资格来开展拟议的工作，因为 Shouval 实验室在与实验组合作建模突触可塑性方面拥有丰富的经验，而 Sacktor 实验室开创了 PKM 科学，并对拟议的技术拥有丰富的经验。实验技术包括测试预测所需的两种新方法。首先，我们建议测试模型对L-LTP中蛋白质翻译的预测，不是通过可能存在毒性和间接影响问题的一般蛋白质合成抑制剂，而是通过使用针对PKM??mRNA翻译起始位点的反义寡脱氧核苷酸来特异性阻断诱导和维持中的PKM??合成。其次，由于 PKM® 介导的增强既高度稳定又可快速逆转，我们将使用专为 L-LTP 维持研究而优化的快流海马切片室来测试模型的关键预测。所提出的平移依赖性双稳定性的随机模拟在计算生物学中也是新颖的。更广泛的影响：作为第一个被证明的大脑中经验依赖性长期信息存储的分子机制，PKM 具有重要的临床意义，并且在去年已被证明有助于多种神经和精神疾病的生物学，包括创伤后应激障碍、中枢神经性疼痛和药物滥用。为了帮助许多实验室对 PKM 的兴趣迅速增长，我们将使我们的模型可供更大的社区使用，允许其他科学家测试、修改并将他们的发现纳入模型中，从而加快科学发现的步伐。由于 NSF 的一个重要目标是将研究和教育结合起来，因此我们将培养多元化的学生。我们的实验室已经培训本科生，Shouval 实验室每年夏天通过 REU 项目（PI S. Cox，Rice）和 UT 系统补助金（PI H. Shouval）招收本科生，全年招收当地本科生，而 Sacktor 实验室在指导当地弱势高中生（例如通过英特尔项目）方面有着悠久的历史。两个实验室都致力于公共宣传；例如，一篇关于 PKM 和内存的文章登上了《纽约时报》的头版。我们渴望将这种类型的推广扩展到生物科学理论与实验之间相互作用的领域。