Determinants of Dendritic Potassium Channel Localization

树突状和体树突状电压门控钾通道或Kv通道是 神经元信号。这项提议旨在确定决定 通过动态调节内在兴奋性的神经元功能。我们特别关注监管 体树突状延迟整流性Kv2.1通道的丰度、分布和功能 树突状A型Kv4.2通道。我们有令人兴奋的新数据，这些数据的本地化和功能 重要的Kv通道受兴奋性神经递质刺激的动态调节，并受 缺氧/缺血。这种调节是通过翻译后对通道蛋白的影响，通过改变 磷酸化状态(Kv2.1、Kv4.2)和与辅助亚基的相互作用(Kv4.2)。此外，动态的 Kv2.1和Kv4.2的变化与神经元电活动的显著变化相关。这项建议是 旨在确定导致Kv2.1本地化和动态变化的确切机制 功能。拟议的项目使用最先进的质谱学方法来确定 通道蛋白上的磷酸化位点，然后通过实验直接解决这样的作用 调节Kv2.1和Kv4.2在异种细胞和神经元中的定位和功能的位点。这个 项目还需要全面分析Kv4.2通道的辅助亚单位在 突触活动对Kv4.2定位和功能的动态调节。最后，我们将直接介入 这些通道的表达和调制以及对神经元电活动的影响 培养和脑切片中。这些研究将对相互的生理学产生重要的见解 调节动态平衡可塑性的Kv2.1和决定活性依赖的Kv4.2 增强功能。

Dendritic and somatodendritic voltage-gated potassium or Kv channels are fundamental components of neuronal signaling. This proposal is aimed at determining the fundamental mechanisms that determine neuronal function through dynamic modulation of intrinsic excitability. We specifically focus on regulation of the abundance, distribution and function of the somatodendritic delayed rectifier Kv2.1 channel, and the dendritic A-type Kv4.2 channel. We have exciting new data that both localization and function of these important Kv channels are dynamically modulated by excitatory neurotransmitter stimulation, and by hypoxia/ischemia. This modulation is via posttranslational effects on the channel proteins, by changes in phosphorylation state (Kv2.1, Kv4.2) and interaction with auxiliary subunits (Kv4.2). Moreover, the dynamic changes in Kv2.1 and Kv4.2 correlate with significant changes in neuronal electrical activity. This proposal is aimed at determining the precise mechanism responsible for the dynamic changes in Kv2.1 localization and function. The proposed project employs state-of-the art mass spectrometric approaches to identify phosphorylation sites on the channel proteins, followed by experiments to directly address the role of such sites in regulating Kv2.1 and Kv4.2 localization and function in both heterologous cells and neurons. The project also entails a comprehensive analysis of the roles of auxiliary subunits of Kv4.2 channels in the dynamic regulation of Kv4.2 localization and function by synaptic activity. Finally, we will directly intervene in the expression and modulation of these channels and determine effects on electrical activity of neurons in culture and in brain slices. These studies will yield important insights into the reciprocal physiological regulation of Kv2.1, a regulator of homeostatic plasticity, and Kv4.2, a determinant of activity-dependent potentiation.