MaxiK channel biology

大电导、钙激活的K+通道(Maxik，BK)是大量细胞的关键调节因子 功能包括血管张力、神经功能和免疫力。因此，知道它们的自然成熟 从合成到建立与蛋白质的相互作用以引导它们到达其功能部位的步骤 是理解其功能基础的关键。因此，这项研究的长期目标是确定 Maxik通道转录、共(翻译后)修饰和流量的调节机制 确定其在正确的时间和地点的可用性和功能。我们已经了解了分子 不同系统中Maxik通道的组成及其通过沉默在动物生理中的作用 亚单位基因，并已开始掌握关于它们的细胞运输机制和它们的 潜在的网络。我们现在要检验的普遍假设是，马克西克的孔道形成亚基(Slo)基因 和蛋白质具有控制其表达、载体运输和蛋白质-脂质相互作用的内在序列 根据生理需要将它们定位在战略细胞隔间中。我们的初步数据 提示：i.MSLO启动子区对雌激素(E_2)有反应，并含有潜在的激素反应 可能由E2控制通道表达的序列；ii.底侧MAXIK靶向可能由SLO驱动 剪接变异插入物；和III.Slo可以肉豆蔻化。我们将使用多学科的方法，特别是， 用于用量子点和高分辨率可视化单分子运动的亲和素-Slo结构 共聚焦显微镜。具体目标是：1)定位转录起始点(S)和功能调控的E2 Slo启动子中的序列(S)，并确定了E2调节Slo的基因组机制(S) 2)研究Slo剪接变异体(S)在决定差异运输和靶向中的作用； 3)研究Maxik肉豆蔻酰化的机制、部位及其功能后果。这些 研究应为调节Maxik通道基因和蛋白的机制提供新的信息 表达和靶向，并确定缓解心脑血管疾病的新治疗途径 疾病。

Large conductance, Ca2+-activated K+ channels (MaxiK, BK) are key regulators of a plethora of cell functions including vascular tone, neuronal function, and immunity. As such, knowing their natural maturation steps from synthesis to the establishment of interactions with proteins that guide them to their functional sites is key to understand the basis of their function. Thus, the long-term goal of this research is to identify the regulatory mechanisms of MaxiK channel transcription, co(post)-translational modifications, and traffic that determine its availability and function at the right time and place. We have learned about the molecular composition of MaxiK channels in different systems, their role in animal physiology by means of silencing subunit genes, and have started to grasp information on the mechanisms of their cellular traffic and on their potential networks. We will now test the general hypothesis that, MaxiK's pore-forming a subunit (Slo) gene and protein have intrinsic sequences that rule their expression, vectorial traffic, and protein-lipid interactions localizing them in strategic cell compartments according to physiological needs. Our preliminary data indicate that: i. mSlo promoter region responds to estrogen (E2) and contains potential hormone-response sequences that may rule channel expression by E2; ii. basolateral MaxiK targeting may be driven by a Slo splice variant insert; and iii.Slo can be myristoylated. We will use a multidisciplinary approach, in particular, avidin-Slo constructs for visualization of single-molecule movements with quantum dots and high resolution confocal microscopy. Specific Aims are to: 1) map the transcription start site(s) and functional E2-regulatory sequences in Slo promoter(s), and define the genomic mechanism(s) of E2-mediated regulation of Slo transcription; 2) investigate the role of Slo splice variant(s) in determining differential trafficking and targeting; and 3) investigate the mechanism and site of MaxiK myristoylation and its functional consequences. These studies should provide new information on the mechanisms that regulate MaxiK channel gene and protein expression and targeting, and identify new therapeutic pathways to alleviate cardio- or cerebro-vascular diseases.