Investigation of experience-dependent post transcriptional regulation of Drosophi

果蝇经验依赖性转录后调控的研究

• 批准号: 9061826
• 负责人: Kausik Si
• 金额: $ 41.25万
• 依托单位: STOWERS INSTITUTE FOR MEDICAL RESEARCH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9061826
• 关键词: Address; Adult; Affect; Amino Acid Substitution; Antigens; Aplysia; Behavioral; Brain; Code; Cognitive deficits; Conditioned Stimulus; Cues; Development; Drosophila genus; Drosophila melanogaster; Episodic memory; Excision; Exposure to; Family; Family member; Food; Functional disorder; Genes; Head; Health; Homologous Gene; Hour; Human; Immunoprecipitation; Introns; Investigation; Learning; Length; Link; Mediating; Memory; Messenger RNA; Molecular; Motor; Mus; Mutation; Neurons; Odors; Organism; Play; Post-Transcriptional Regulation; Process; Production; Protein Biosynthesis; Protein Isoforms; Proteins; RNA Splicing; RNA-Binding Proteins; Reporter; Role; Sensory; Serotonin; Short-Term Memory; Starvation; Stimulus; Sucrose; Synapses; Synaptic plasticity; Syndrome; System; Terminator Codon; Training; Transcript; Transcription Initiation Site; Translating; addiction; antigen binding; base; crosslink; experience; fly; in vivo; insight; knock-down; long term memory; memory process; mutant; neuroregulation; overexpression; protein expression; response; stem

DESCRIPTION (provided by applicant): Although a large number of experiences produce transient memory only some of them form stable long-term memory. The value of the experience and internal state of the organism plays an important role in determining this transition from short-term to long-term memory. However, how external experience and the internal state of the organism interact at a molecular level to influence memory storage is largely unknown. The synthesis of new proteins is required to form stable long-term memory. CPEB, a family of RNA-binding proteins, regulate activity-dependent protein synthesis in the neuron. In Aplysia, a specific CPEB family member, ApCPEB, is required for the persistence of activity-dependent increase in synaptic strength beyond 24 hours. In Drosophila, a CPEB family member Orb2 is required to stabilize memory beyond 12 hours. In mice and human a CPEB family member CPEB3 has been linked to episodic memory formation. These observations suggest that CPEB family members play evolutionarily conserved role in the persistence of memory. The Drosophila Orb2 gene produces two distinct primary transcripts from two different transcription start sites, encoding the Orb2A and Orb2B proteins. Mutations that selectively inactivate Orb2A protein specifically destabilize long-term memory. We have found that the Orb2A mRNA has two forms; an intron containing unspliced form that does not code for Orb2A protein (Orb2A-np) and a spliced form that codes for full length Orb2A protein (Orb2A-pc). Surprisingly, the Orb2A-np mRNA is the prevalent isoform in the adult brain and exposure to cues that form associative long-term memory in flies, such as exposure of hungry flies to sucrose and odor increases the level of protein coding spliced Orb2A-pc transcript. The Drosophila orthologue of mammalian splicing regulator Nova binds Orb2A transcript and regulates the formation of Orb2A-pc mRNA. In this proposal we intend to dissect the behavioral cues and Nova-dependent molecular mechanism that regulate the level of protein coding Orb2A transcript. We also intend to address when and how long Orb2 proteins are required for persistence of memory. We hope that an understanding of the interaction of experiences and molecules that stabilize memory would be useful to understand addictions and post traumatic syndromes, in which a single experience forms extremely stable memory. Also, we hope to gain insight into the role of regulated mRNA processing in long-lasting memory.

描述（由申请人提供）：虽然大量的经历会产生短暂的记忆，但其中只有一些会形成稳定的长期记忆。有机体的经验和内部状态的价值在决定从短期记忆到长期记忆的转变中起着重要作用。然而，外部经验和生物体的内部状态如何在分子水平上相互作用以影响记忆存储在很大程度上是未知的。 未知。新蛋白质的合成是形成稳定的长期记忆所必需的。 CPEB 是 RNA 结合蛋白家族，调节神经元中活性依赖性蛋白的合成。在海兔中，特定的 CPEB 家族成员 ApCPEB 是活动依赖性突触强度持续增加超过 24 小时所必需的。在果蝇中，需要 CPEB 家族成员 Orb2 来稳定记忆超过 12 小时。在小鼠和人类中，CPEB 家族成员 CPEB3 与情景记忆的形成有关。这些观察结果表明 CPEB 家族成员在记忆的持久性中发挥着进化保守的作用。果蝇 Orb2 基因从两个不同的转录起始位点产生两个不同的初级转录物，编码 Orb2A 和 Orb2B 蛋白。选择性失活 Orb2A 蛋白的突变会特异性破坏长期记忆的稳定性。我们发现Orb2A mRNA有两种形式；包含不编码 Orb2A 蛋白的未剪接形式 (Orb2A-np) 和编码全长 Orb2A 蛋白 (Orb2A-pc) 的剪接形式的内含子。令人惊讶的是，Orb2A-np mRNA 是成人大脑中普遍存在的亚型，暴露于果蝇中形成联想长期记忆的线索，例如将饥饿的果蝇暴露于蔗糖和气味中，会增加编码剪接 Orb2A-pc 转录物的蛋白质编码水平。哺乳动物剪接调节因子 Nova 的果蝇直系同源物结合 Orb2A 转录物并调节 Orb2A-pc mRNA 的形成。在本提案中，我们打算剖析调节 Orb2A 转录物编码蛋白水平的行为线索和 Nova 依赖性分子机制。我们还打算解决 Orb2 蛋白何时以及需要多长时间来维持记忆。我们希望了解经验和稳定记忆的分子之间的相互作用将有助于理解成瘾和创伤后综合症，在这些综合症中，单一的经历会形成极其稳定的记忆。此外，我们希望深入了解受调控的 mRNA 加工在持久记忆中的作用。