Neurochemistry and Genetics of Drosophila CaMKII

描述（由申请人提供）：突触蛋白水平和活性的局部调节对可塑性至关重要。在本文中，我们研究了翻译在CaMKII水平调控中的作用，并描述了Eag和dCASK与CaMKII相互作用的功能角色。果蝇的遗传工具使我们能够将生物化学研究的结果应用于理解行为的新策略的设计。明确目标#1。CaMKII的翻译控制与可塑性。CaMKII的新合成对长期记忆很重要，而且许多新合成定位于突触区域。定位和调控合成发生的机制刚刚开始被阐明，rasi/siRISC途径（苍蝇）和CPEBP途径（啮齿动物和我们的初步结果）都涉及到。在这个目标中，我们将确定哪些过程调节CaMKII合成以及它们如何与行为相关。具体目标2。Eag在可塑性中的非通道作用。Eag是电压门控钾通道，但在果蝇中，该通道的突变会影响多个电流。我们已经确定了Eag位点的替代产物，该产物是在响应多种信号转导途径的激活时产生的，并编码具有核信号传导潜力的非通道蛋白。我们将确定这种蛋白是否直接作用于突触和/或它是否调节基因表达。具体目标#3。dCASK调控CaMKII自磷酸化的行为效应。dCASK调控CaMKII的自磷酸化。当突触活性低时，通过增加T306磷酸化（阻断CaM结合），该蛋白可以下调无活性突触中CaMKII的可激活库。T306磷酸化也会影响CaMKII上的“记忆”位点T287随后的磷酸化：阻断其进入活性状态的转换。因此，dCASK是CaMKII钙依赖性和钙非依赖性活性的“增益控制器”。在这个目的中，我们将使用dCASK来调节体内CaMKII自磷酸化水平，并评估学习和记忆的形成。这些研究将为突触过程的局部和遗传调控提供见解。理解这些过程是理解行为的基础。

DESCRIPTION (provided by applicant): Local regulation of the levels and activity of synaptic proteins is critical to plasticity. In this proposal, we investigate the role of translation in regulation of the levels of CaMKII and characterize the functional roles of the interaction of Eag and dCASK with CaMKII. The genetic tools available in Drosophila allow us to apply the results of our biochemical studies to the design of novel strategies for understanding behavior. Specific Aim #1. Translational control of CaMKII and plasticity. New synthesis of CaMKII is important for long-term memory, and much of the new synthesis is localized to synaptic regions. The mechanisms by which localization and regulated synthesis occurs are just beginning to be elucidated and both the rasi/siRISC pathway (flies) and CPEBP pathway (rodents and our preliminary results) have been implicated. In this aim we will determine what processes regulate CaMKII synthesis and how they relate to behavior. Specific Aim #2. Non-channel role of Eag in plasticity. Eag is a voltage-gated potassium channel, but in Drosophila, mutants in this channel affect multiple currents. We have identified an alternative product of the Eag locus that is produced in response to activation of multiple signal transduction pathways and encodes a non-channel protein with potential for nuclear signaling. We will determine if this protein functions directly at synapses and/or whether it regulates gene expression. Specific Aim #3. Behavioral effects of dCASK regulation of CaMKII autophosphorylation. dCASK regulates the autophosphorylation of CaMKII. By increasing T306 phosphorylation (which blocks CaM binding) when synaptic activity is low, this protein can downregulate the activatable pool of CaMKII at synapses that are inactive. T306 phosphorylation also has an impact on subsequent phosphorylation of T287, the 'memory' site on CaMKII: blocking switching into the active state. dCASK is therefore a 'gain controller' for both the calcium-dependent and calcium-independent activities of CaMKII. In this aim we will use dCASK to modulate the levels of CaMKII autophosphorylation in vivo and assess learning and memory formation. These studies will provide insight into local and genetic regulation of synaptic processes. Understanding these processes is fundamental to understanding behavior.