Roles and mechanisms of Slo and Slack Channels in Brain

描述（由申请人提供）：一类钙激活 钾离子通道BK（Ca）通道在突触前富集， 大脑中的神经递质释放位点，并被认为控制 神经递质释放的数量和时间。BK（Ca）通道 由Slo基因编码最近的证据表明，一个相关的基因，松弛， 也有助于神经元中的BK（Ca）样通道，并且一些BK（Ca） 通道可以由Slo和Slack通道的异多聚体组成 亚单位。本提案中的实验将表征分子， BK（Ca）通道的生物物理和结构特性， 天然神经元的突触前末梢和转染细胞中。的作用 正常突触传递中的Slo和Slack通道亚基，以及 它们对缺氧的反应机制，将通过膜片钳来确定 测量结合基因敲除方法。结构和 Slo通道大羧基末端调控区的功能 亚基及其钙结合位点，以及它与其他 蛋白质，包括Slack亚基，将通过生物物理和生物化学方法来确定。 生物化学测量和X射线晶体学方法。最后 完整BK（Ca）通道的结构将通过以下方法确定： 冷冻电镜分子特性和调控的知识 BK（Ca）通道在正常和缺氧神经元，连同结构 确定它们与药物和天然配体的相互作用，将 是开发更有效治疗疾病的关键， 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.