CONTROL OF PROTEIN SYNTHESIS-DEPENDENT SYNAPTIC PLASTIC

这个项目的总体目标是了解构成学习和记忆基础的依赖蛋白质合成的突触修饰。已经证实，活动刺激蛋白质的合成，其中一些蛋白质是由定位于突触或突触附近的mRNA合成的。研究人员最近描述了一种新的经验驱动的局部翻译机制，其中翻译休眠的突触mRNA通过细胞质多腺化元件结合蛋白(CPEB)的作用被多腺化。这一发现为研究局部mRNA翻译在突触可塑性中的作用提供了一个前所未有的机会，并为连贯、完整和广泛地研究依赖于蛋白质合成的突触可塑性的调控奠定了基础。项目1(Richter)包括利用Cre-loxP技术鉴定新的CPEB亚型和一种新的靶向CPEB基因敲除小鼠；以及鉴定其他CPEB调节的mRNAs。项目2(Fallon)包括CPEB在发育中的成人大脑和培养的海马神经元中在光和EM水平上的定位；从突触激活到细胞质聚腺苷酸化的细胞内信号通路的特征；以及含CPE的mRNAs和CPEB靶向树突的调节。项目3(Bear)将描述一种新形式的蛋白质合成依赖的突触可塑性(DHPG-LTD)；使用缺乏CPEB的小鼠进行巩固；并表征局部翻译和CPEB在NMDA受体亚单位表达的经验依赖调节中的作用。将有两个核心，一个用于管理，另一个用于生产和维护CPEB基因敲除小鼠，所有调查人员都将使用这两个核心。这些应该有助于更好地理解长期记忆形成的机制。这些结果可以提供理解影响学习和记忆的疾病所需的洞察力，并可能有助于设计抗击这些疾病的治疗策略。

The overall goal of this Program is to understand the protein synthesis- dependent synaptic modifications that underlie learning and memory. It has been established that activity stimulates protein synthesis, and that some of these proteins are synthesized from mRNA localized at or near the synapse. The investigators recently described a novel mechanism for such experience-driven local translation wherein translationally dormant synaptic mRNA is polyadenylated through the action of the CPEB (cytoplasmic polyadenylation element binding protein). This discovery provides an unprecedented opportunity to study the role of local mRNA translation in synaptic plasticity, and forms the basis for a coherent, integrated, and broadly-based investigation into the regulation of protein synthesis-dependent synaptic plasticity. Project 1 (Richter) includes the characterization of new CPEB isoforms and a novel targeted CPEB knock-out mouse using Cre-loxP technology; and the identification of additional CPEB-regulated mRNAs. Project 2 (Fallon) includes the localization, at the light and EM level, of CPEB in developing an adult brain, and in cultured hippocampal neurons; the characterization of the intracellular signaling pathways leading from synaptic activation to cytoplasmic polyadenylation; and the regulation of the targeting of CPE- containing mRNAs and of CPEB to dendrites. Project 3 (Bear) will characterize a noel form of protein synthesis-dependent synaptic plasticity (DHPG-LTD); use mice lacking CPEB in the consolidation; and characterize the role of local translation and CPEB in experience- dependent regulation of NMDA receptor subunit expression. There will be two cores, one administrative and the second for the production and maintenance of CPEB knock-out mice, which will be used by all the investigators. These should lead to better understanding of the mechanisms of long-term memory formation. The results could provide insights needed to understand diseases that affect learning and memory, and may be useful in designing therapeutic strategies to combat them.