Molecular bases of BK channel function and localization

BK通道功能和定位的分子基础

• 批准号: 8197884
• 负责人: ZHAO-WEN WANG
• 金额: $ 30.49万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-01 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8197884
• 关键词: Biological Assay; Biotin; Caenorhabditis elegans; Cerebellar Ataxia; Chimeric Proteins; Chromosome Mapping; Disease; Disease Management; Drosophila genus; Engineering; Epilepsy; Erectile dysfunction; Excretory function; Fluorescence; Functional disorder; Future; Genes; Genetic Screening; Genome; Goals; Haploidy; Health; Homologous Gene; Human; Hypertension; Immunohistochemistry; Interneurons; Kidney; Knowledge; Label; Mammals; Membrane; Mink; Molecular; Molecular Genetics; Muscle; Muscle Cells; Mutation; Names; Nervous system structure; Neuromuscular Junction; Neurons; Overactive Bladder; Paroxysmal Dyskinesias; Peptides; Phenotype; Physiological; Presynaptic Terminals; Property; Protein Isoforms; Proteins; Research; Screening procedure; Site; Surface; Synapses; System; Testing; Western Blotting; Xenopus oocyte; base; density; gain of function; genetic regulatory protein; glomerular filtration; hearing impairment; in vivo; large-conductance calcium-activated potassium channels; loss of function mutation; mutant; neurotransmitter release; novel; postsynaptic; presynaptic; programs; research study; voltage

DESCRIPTION (provided by applicant): BK channels are almost ubiquitously expressed and perform many important physiological functions. Dysfunction of the channel causes a variety of diseases, including epilepsy, progressive hearing loss, cerebellar ataxia, and hypertension. The function of BK channels depends on proper subcellular localization and interactions with auxiliary or regulatory proteins. However, the molecular basis of BK channel subcellular localization is unknown and only limited knowledge exists about BK channel auxiliary/regulatory proteins. The powerful molecular genetics of C. elegans is explored to identify proteins important to BK channel function or subcellular localization. In preliminary studies, mutants of three genes (named as bkip-1, bkip-2 and bkip-3) were isolated as suppressors of a lethargic phenotype caused by expressing a gain-of-function (gf) isoform of SLO-1, the C. elegans BK channel. Phenotypes of these mutants included increased neurotransmitter release (bkip-1) and SLO-1 mislocalization (bkip-2 and bkip-3). bkip-1 and bkip-2 were found to encode novel BK channel- interacting proteins whereas bkip-3 remains to be identified. BKIP-1 showed several effects on SLO-1 functional properties when analyzed in a heterologous expression system. This proposal is to test the hypotheses that the three BKIPs are important to SLO-1 function and/or subcellular localization in vivo and that there are other functionally related proteins in C. elegans. The specific aims of this proposal are: (1) determine how BKIP-1 regulates SLO-1 function; (2) determine how BKIP-2 and BKIP-3 control SLO-1 subcellular localization and/or function, and (3) isolate and identify additional mutants that suppress the lethargic phenotype caused by SLO-1(gf), which will be analyzed in future studies. The long-term goal is to elucidate the molecular basis of BK channel function and subcellular localization. PUBLIC HEALTH RELEVANCE: Mutations of the BK channel cause a variety of diseases, including epilepsy, hypertension, progressive hearing loss, cerebellar ataxia, overactive bladder, penile erectile dysfunction, impaired renal glomerular filtration and K+ excretion, and paroxysmal dyskinesia. The proposed research program may identify novel proteins that are important to BK channel function and/or subcellular localization in vivo. Such information is potentially of great value to understanding the molecular bases of BK channel-related diseases, and to identifying candidate pharmacological targets for the treatment and management of these diseases.

描述（由申请人提供）：BK 通道几乎普遍表达并执行许多重要的生理功能。该通道的功能障碍会导致多种疾病，包括癫痫、进行性听力损失、小脑性共济失调和高血压。 BK 通道的功能取决于正确的亚细胞定位以及与辅助或调节蛋白的相互作用。然而，BK 通道亚细胞定位的分子基础尚不清楚，并且关于 BK 通道辅助/调节蛋白的知识也很有限。探索线虫强大的分子遗传学来鉴定对 BK 通道功能或亚细胞定位重要的蛋白质。在初步研究中，三个基因（称为 bkip-1、bkip-2 和 bkip-3）的突变体被分离出来，作为因表达 SLO-1 的功能获得（gf）亚型而引起的昏睡表型的抑制子，SLO-1 是线虫 BK 通道。这些突变体的表型包括神经递质释放增加 (bkip-1) 和 SLO-1 错误定位 (bkip-2 和 bkip-3)。发现 bkip-1 和 bkip-2 编码新型 BK 通道相互作用蛋白，而 bkip-3 仍有待鉴定。在异源表达系统中进行分析时，BKIP-1 显示出对 SLO-1 功能特性的多种影响。该提案旨在测试以下假设：这三种 BKIP 对 SLO-1 功能和/或体内亚细胞定位很重要，并且秀丽隐杆线虫中还存在其他功能相关的蛋白质。该提案的具体目标是：（1）确定BKIP-1如何调节SLO-1功能； (2) 确定 BKIP-2 和 BKIP-3 如何控制 SLO-1 亚细胞定位和/或功能，以及 (3) 分离并鉴定抑制 SLO-1(gf) 引起的昏睡表型的其他突变体，并将对其进行分析在以后的学习中。长期目标是阐明 BK 通道功能和亚细胞定位的分子基础。公共健康相关性：BK 通道突变可导致多种疾病，包括癫痫、高血压、进行性听力损失、小脑性共济失调、膀胱过度活动症、阴茎勃起功能障碍、肾小球滤过和 K+ 排泄受损以及阵发性运动障碍。拟议的研究计划可能会鉴定对 BK 通道功能和/或体内亚细胞定位很重要的新型蛋白质。这些信息对于了解 BK 通道相关疾病的分子基础以及确定治疗和管理这些疾病的候选药理学靶点具有潜在的重要价值。