Regulation and Neural Function of Atypical PKC

非典型PKC的调节和神经功能

• 批准号: 8661284
• 负责人: TODD C SACKTOR
• 金额: $ 39.88万
• 依托单位: SUNY DOWNSTATE MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8661284
• 关键词: 1,2-diacylglycerol; AMPA Receptors; Affect; Behavior; Behavioral; Binding; Binding Sites; Brain; C-terminal; Catalytic Domain; Chemosensitization; Cyclic AMP-Dependent Protein Kinases; Data; Dendrites; Diglycerides; Disease; Dominant-Negative Mutation; Endocytosis; Exocytosis; Funding; Genes; Genetic; Genetic Transcription; GluR2 subunit AMPA receptor; Goals; Grant; Hippocampus (Brain); Hour; Information Storage; Knowledge; Laboratories; Lead; Length; Long-Term Potentiation; MAP Kinase Gene; Maintenance; Mediating; Memory; Memory Disorders; Messenger RNA; Modification; Molecular; N-terminal; Neurobiology; Neurology; Neurons; Neurophysiology - biologic function; Pathway interactions; Perfusion; Phase; Phosphotransferases; Protein Isoforms; Protein Kinase; Protein Kinase C; Proteins; Psychiatry; Pyramidal Cells; Regulation; Rodent; Role; Second Messenger Systems; Signaling Molecule; Site; Synapses; Synaptic Transmission; Synaptic plasticity; Testing; Time; Training; Translating; Translations; Work; atypical protein kinase C; calmodulin-dependent protein kinase II; inhibitor/antagonist; long term memory; overexpression; postsynaptic; prevent; promoter; protein transport; receptor; receptor function; second messenger; trafficking

DESCRIPTION (provided by applicant): Long-term memories are believed to be due to persistent changes in synaptic strength. Although the molecular mechanisms initiating these changes have been extensively studied, the mechanisms maintaining these changes, which may contribute to storing long-term memory, have been unknown. Recently, however, a candidate molecular mechanism has emerged for maintaining a persistent form of synaptic enhancement triggered by strong afferent stimulation of synapses, known as long-term potentiation (LTP). The key molecule in this maintenance mechanism is a brain-specific, protein kinase C isoform, PKM6. Unlike other PKC isoforms that require second messengers for activation, PKM6 consists of an independent PKC catalytic domain that is constitutively active. PKM6 is produced from a PKM6 mRNA, and the amount of the kinase increases with LTP induction. The persistent activity of the kinase is then both necessary and sufficient for maintaining the synaptic enhancement. Postsynaptic perfusion of PKM6 enhances synaptic transmission, and inhibition of PKM6 activity reverses previously established LTP. Recently, PKM6 inhibition has been found to disrupt the storage of previously established long-term memories. These data indicate that PKM6 is a candidate molecule uniquely important for information storage at synapses and during behavior. Thus the overall goal of this application is to elucidate in mechanistic detail the function of PKM6 in persistent synaptic enhancement and memory storage. Our 3 Specific Aims are: 1) To characterize the mechanisms by which PKM6 enhances synaptic strength. We found that PKM6 potentiates synaptic strength by increasing the number of postsynaptic AMPA receptors (AMPARs) through interactions between the AMPAR GluR2 subunit and the trafficking protein NSF. We will examine whether this potentiation is through increased exocytosis and/or decreased endocytosis of postsynaptic AMPARs and the function of this altered trafficking in memory maintained by PKM6. 2) To determine whether preexisting and newly translated PKM6 mediate distinct phases of potentiation during LTP. Preliminary evidence indicates that antisense oligodeoxynucleotides blocking new PKM6 synthesis prevents the persistence of a phase of LTP. We will determine whether this new synthesis occurs at dendritic sites. 3) To determine the role of preexisting, newly translated, and new gene transcription of PKM6 in distinct phase of memory. PKM6 maintains memory up to several months after training. We will employ both antisense to block translation of PKM6 mRNA and conditional genetic deletion of PKM6 to examine the function of distinct mechanisms of expression of PKM6 in different phases of memory. These 3 aims will provide fundamental new information on a potential molecular mechanism for maintaining synaptic and behavioral information storage, which may be relevant to both normal memory and its disorders.

描述（由申请人提供）：认为长期记忆是由于突触强度的持续变化所致。尽管已经对启动这些变化的分子机制进行了广泛的研究，但维持这些变化的机制（可能有助于存储长期记忆）的机制尚不清楚。然而，最近，出现了一种候选分子机制，用于维持由强烈传入的突触刺激（称为长期增强（LTP））触发的突触增强的持续形式。该维护机制中的关键分子是一种脑特异性的蛋白激酶C同工型，PKM6。与需要第二个使者激活的其他PKC同工型不同，PKM6由组成型活性的独立PKC催化域组成。 PKM6由PKM6 mRNA产生，激酶的量随LTP诱导而增加。然后，激酶的持续活性是维持突触增强的必要和足够的。 PKM6的突触后灌注增强了突触传播，PKM6活性的抑制作用逆转了先前已建立的LTP。最近，已经发现PKM6抑制会破坏先前确定的长期记忆的存储。这些数据表明，PKM6是候选分子对于突触和行为过程中的信息存储至关重要。因此，该应用程序的总体目标是在机械详细信息中阐明PKM6在持续的突触增强和内存存储中的功能。我们的3个具体目标是：1）表征PKM6增强突触强度的机制。我们发现，PKM6通过通过AMPAR GLUR2亚基与运输蛋白NSF之间的相互作用来增加突触后AMPA受体（AMPAR）的数量来增强突触强度。我们将检查这种增强是否是通过增加突触后AMPAR的胞吐作用和/或降低的内吞作用以及PKM6维持的记忆中这种变化的记忆的功能。 2）确定先前存在和新翻译的PKM6是否介导了LTP期间的不同阶段。初步证据表明，反义寡脱氧核苷酸阻断新的PKM6合成可防止LTP阶段的持续性。我们将确定这种新合成是否发生在树突位点。 3）确定PKM6在不同记忆阶段的前提，新翻译和新基因转录的作用。 PKM6在训练后长达几个月保持记忆力。我们将使用两种反义来阻止PKM6 mRNA的翻译和PKM6的条件遗传缺失来检查PKM6在不同阶段的不同阶段的表达不同机制的功能。这三个目标将提供有关维持突触和行为信息存储的潜在分子机制的基本新信息，这可能与正常记忆及其疾病有关。