Mutants Showing SLO-1 Synaptic Mislocalization

描述（由申请人提供）：大电导钙激活钾通道（BK通道，Soll）是神经末梢的一种重要离子通道。BK通道与钙通道共定位于突触前活动区，并作为神经递质释放的有效调节剂。BK通道的功能受多种因素的调节，这表明该通道在突触可塑性中具有潜在的重要作用。由于适当的亚细胞定位对于BK通道功能可能是至关重要的，因此确定如何实现BK通道突触定位是重要的。明确BK通道突触靶向和定位的机制将是我们理解突触结构和功能的一个重大进展。 In C.在线虫中，BK通道（SLO-1）的功能丧失突变导致神经递质释放增加（Wang等人，2001），表明SLO-1的正常功能是下调释放。类似于其他物种的BK通道，SLO-1定位于神经系统中的突触区域（Wang等人，2001年）。这种有限的分布模式改变为弥漫性表达的神经元后，修改的SLO-1的羧基末端。该建议旨在验证BK通道突触前定位是由特定的转运和支架分子介导的假设。具体而言，将进行遗传筛选以分离显示GFP标记的SLO-1转基因在C.优雅在后续研究中对这些突变体的分析可能允许鉴定介导SLO-1突触靶向和定位的分子。

DESCRIPTION (provided by applicant): The large-conductance calcium-activated potassium channel (BK channel, Slol) is a prominent ion channel at nerve terminals. BK channels co-localize with calcium channels at the presynaptic active zone, and serve as a potent regulator of neurotransmitter release. The function of BK channels is regulated by many factors, suggesting that the channel is potentially an important player in synaptic plasticity. Since proper subcellular localization is likely critical for BK channel function, it is important to determine how BK channel synaptic localization is achieved. Defining the mechanism of BK channel synaptic targeting and localization would be a significant advance in our understanding of synaptic structure and function. In C. elegans, loss-of-function mutations of the BK channel (SLO-1) results in increased neurotransmitter release (Wang et al., 2001), suggesting that the normal function of SLO-1 is to downregulate the release. Similar to BK channels of other species, SLO-1 is localized to synaptic regions in the nervous system (Wang et al., 2001). This restricted distribution pattern was changed to diffuse expression in neurons following a modification of the SLO-1 carboxyl terminus. This proposal seeks to test the hypothesis that presynaptic localization of BK channels is mediated by specific transport and scaffold molecules. Specifically, a genetic screen will be performed to isolate mutants showing mislocalization of a GFP-tagged SLO-1 transgene in C. elegans. Analysis of these mutants in subsequent studies may allow the identification of molecules mediating SLO-1 synaptic targeting and localization.