Roles and mechanisms of Slo and Slack Channels in Brain

描述(申请人提供)：钙激活的一类 被称为BK(Ca)通道的钾通道在突触前被丰富 大脑内的神经递质释放部位，据信控制着 神经递质释放的数量和时间。BK(Ca)通道为 由Slo基因编码。最近的证据表明，一种相关基因，松弛， 也参与了神经元上的BK(Ca)样通道，而且一些BK(Ca) 通道可以由Slo和Slack通道的异质多聚体组成 亚单位。这个方案中的实验将描述分子的特征， 体细胞内BK(Ca)通道的生物物理和结构特性 天然神经元和转基因细胞的突触前终末。的作用 正常突触传递中的Slo和Slack通道亚单位，以及 它们对低氧的反应机制将通过膜片钳来确定 测量与基因敲除方法相结合。它的结构和 Slo通道大羧基末端调控区的功能 亚基及其与钙结合部位的相互作用 蛋白质，包括松弛亚单位，将由生物物理和 生化测量和X射线结晶学方法。最后是 完整的BK(Ca)通道的结构将由 低温电子显微镜。对分子性质和调控的知识 正常和低氧神经元的BK(Ca)通道及其结构 对它们与药物和天然配体相互作用的测定，将 在开发更有效的疾病治疗方法方面发挥关键作用，例如 癫痫和中风。

DESCRIPTION (provided by applicant): A class of calcium-activated potassium channels termed BK(Ca) channels are enriched at presynaptic neurotransmitter release sites within the brain, and are believed to control both the amount and timing of neurotransmitter release. BK(Ca) channels are encoded by the Slo gene. Recent evidence suggests that a related gene, Slack, also contributes to BK(Ca)-like channels in neurons, and that some BK(Ca) channels may be comprised of heteromultimers of Slo and Slack channels subunits. The experiments in this proposal will characterize the molecular, biophysical and structural properties of BK(Ca) channels in both the somata and presynaptic terminals of native neurons, and in transfected cells. The role of the Slo and Slack channel subunits in normal synaptic transmission, and the mechanisms of their response to hypoxia, will be determined by patch clamp measurements coupled with genetic knockout approaches. The structure and function of the large carboxy-terminal regulatory region of the Slo channel subunit with its calcium-binding sites, and its interaction with other proteins, including the Slack subunit, will be determined by biophysical and biochemical measurements and by X-ray crystallographic methods. Finally the structure of intact BK(Ca) channels will be determined by cryo-electronmicroscopy. Knowledge of the molecular properties and regulation of BK(Ca) channels in normal and hypoxic neurons, together with structural determinations of their interactions with both drugs and natural ligands, will be key in the development of more effective treatments for disorders such as epilepsy and stroke.