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: 9059060
• 负责人: HAREL Zeev SHOUVAL
• 金额: $ 28.46万
• 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 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9059060
• 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; Feedback; Goals; Grant; High School Student; Hippocampus (Brain); Hour; Housing; Human; In Vitro; Information Storage; Instruction; Kinetics; Knowledge; Learning; Life; Long-Term Potentiation; Maintenance; Mediating; Memory; Mental disorders; Mentors; Methodology; Modeling; Molecular; Molecular Conformation; 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 Synthesis Inhibitors; Proteins; Qualifying; Recording of previous events; Regulation; Rice; Role; Science; Scientist; Site; Slice; Solid; Students; Synapses; Synaptic Transmission; Synaptic plasticity; System; Techniques; Testing; Theoretical model; Time; Toxic effect; Training; Translations; Work; Youth; abstracting; addiction; base; biophysical model; drug reward; drug seeking behavior; education research; experience; field study; in vivo; inhibitor/antagonist; interest; link protein; long term memory; mathematical model; nervous system disorder; neuronal circuitry; 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 Mζ(PKMζ), 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 PKMζcan overcome the natural degrading effect of protein turnover and diffusion. The central hypothesis of this proposal is that PKMζ, 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 PKMζ-mediated persistent synaptic potentiation, using novel techniques tailored for testing the theory. Intellectual Merit: The finding that PKMζ 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 PKMζmRNA to specifically block PKMζ synthesis in induction and maintenance. Second, because PKMζ-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, PKMζ 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 PKMζ 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 PKMζ 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青年时代的记忆；我们记得四岁时住的房子；我们记得一位最喜欢的老师。储存这些记忆的机制被认为是特定神经元回路中突触连接的长期可塑性。然而，这种假定的记忆的细胞基础依赖于通常比记忆寿命短得多的蛋白质。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储存人类一生的记忆？最近，研究表明，脑特异性PKC异构体蛋白激酶Mζ(PKMζ)在维持突触的后期长期增强（L-LTP）和长期记忆中起着独特的作用。然而，这一重要的观察结果并不能解释pkm - ζ如何克服蛋白质周转和扩散的自然降解作用。该提议的中心假设是PKMζ，通过控制其自身的合成，可以形成一个双稳定的系统，这可以解释突触特定的长期可塑性和记忆的维持。在此，我们提出在生物物理模型中以数学方式表达这一假设，并对该模型进行分析，从而提出可测试的实验预测。然后，我们将使用专为测试该理论而定制的新技术，直接测试这些关于pkm - ζ介导的持续突触增强的预测。智力优势：发现PKMζ对于突触可塑性和长期记忆的维持是必要和充分的，这从根本上改变了学习和记忆领域，但是关于能够真正实现长期可塑性和记忆的持久性的机制还需要了解很多。本建议采用理论与实验相结合的方法来解决这些问题。这种双稳定性依赖于翻译调节的理论不仅对神经科学而且对一般生物学都是新颖的。我们的合作是唯一有资格开展所提出的工作，因为Shouval实验室在与实验组合作建模突触可塑性方面有丰富的经验，而Sacktor实验室是PKM科学的先驱。并且对所建议的技术有丰富的经验。实验技术包括两种测试预测所必需的新方法。首先，我们建议测试该模型对L-LTP中蛋白质翻译的预测，不是通过可能具有毒性和间接作用的一般蛋白质合成抑制剂，而是通过使用反义寡脱氧核苷酸指向pkm - ζ mrna的翻译起始位点，特异性阻断pkm - ζ在诱导和维持中的合成。其次，由于pkm - ζ介导的增强既高度稳定又快速可逆，我们将使用针对L-LTP维持研究优化的快流海马切片室来测试该模型的关键预测。翻译依赖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：作为第一个证明经验依赖的分子机制，PKMζ具有重要的临床意义，在过去的一年中，PKMζ已被证明在多种神经和精神疾病的生物学中起作用，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PKMζ快速增长的兴趣，我们将使我们的模型对更大的社区开放，允许其他科学家测试，修改，并将他们的发现纳入模型，从而加快科学发现的步伐。因为NSF的一个重要目标是整合研究和教育，我们将培养多样化的学生。我们的实验室已经在培训本科生，Shouval实验室每年夏天通过REU项目（PI S. Cox, Rice）和UT系统资助项目（PI H. Shouval）招收本科生，并全年招收当地本科生，Sacktor实验室在指导当地弱势高中生方面有着悠久的历史（例如，通过英特尔项目）。这两个实验室都致力于向公众推广；例如，一篇关于PKMζ和记忆的文章出现在《纽约时报》的头版。我们渴望将这种拓展扩展到生物科学理论与实验之间的相互作用领域。