Molecular and anatomical basis of sleep regulation by SLEEPLESS

SLEEPLESS 睡眠调节的分子和解剖学基础

• 批准号: 8417679
• 负责人: William J Joiner
• 金额: $ 32.61万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-15 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8417679
• 关键词: Address; Affect; Amino Acids; Arousal; Behavior; Binding; Biochemical; Biological Assay; Biological Models; Biological Process; Brain; Brain region; Cell membrane; Cell surface; Cells; Circadian Rhythms; Complex; Coupled; Couples; Data; Defect; Disease; Drosophila genus; Drosophila melanogaster; Electroencephalography; Electrophysiology (science); Evolution; Family; Family member; Genes; Genetic Models; Genetic Screening; Genome; Health; Homeostasis; Homologous Gene; Human; Human Pathology; Impairment; Ion Channel; Kinetics; Link; Mammals; Measures; Membrane; Molecular; Mus; Mutation; Neurons; Neurotoxins; Orthologous Gene; Output; Pathway interactions; Phenotype; Potassium Channel; Process; Property; Protein Isoforms; Proteins; RNA Editing; Recovery; Recycling; Regulation; Role; Signal Transduction; Sleep; Sleep Deprivation; Sleep Disorders; Surface; Testing; Time; Transcript; Transgenes; Voltage-Gated Potassium Channel; Work; awake; base; cholinergic; fly; high throughput screening; improved; in vitro testing; member; mutant; neural circuit; neuronal excitability; novel; promoter; public health relevance; sleep regulation; trafficking

DESCRIPTION (provided by applicant): Sleep is an essential, evolutionarily conserved process which, if unfulfilled, contributes to human pathology. The importance of sleep is underscored by its tight homeostatic control: sleep drive increases with time spent awake and dissipates with time spent asleep. However, the molecular mechanisms underlying regulation of sleep and the neural circuitry that controls sleep homeostasis are largely unknown. The fruit fly, Drosophila melanogaster, which has proven useful for identifying genes involved in behavior, human health and disease, has also emerged as a valuable genetic model system for studying sleep. Using a forward genetic screen, we identified the novel gene sleepless (sss) that is required for both baseline and homeostatic recovery sleep following sleep deprivation. In sss mutants, we found that levels of the sleep-regulating K channel, Shaker (Sh), are reduced, leading to the hypothesis that sss couples sleep drive to lowered membrane excitability. More recently we have also shown that sss can regulate the localization of Sh channels in addition to both amplitude and kinetics of Sh currents. Consistent with direct regulation of Sh by SSS, we have demonstrated that Sh expression is promoted post-transcriptionally via the formation of a stable complex between channel and SSS. sss is under the control of RNA editing machinery, and edited sss is less effective than uneditable sss at promoting sleep. We thus hypothesize that RNA editing controls the ability of SSS to interact with Sh, thereby altering activity and subcellular trafficking of the channel. The structural basis for SSS-Sh interactions is particularly intriguing: SSS is one of the founding members of a large family of relatively uncharacterized proteins that resemble neurotoxins, which often act on ion channels, raising the possibility that other members of this family may regulate excitability and sleep. The focus of this proposal is to determine the molecular basis of sleep regulation by sss, particularly with regard to Sh, and to describe the neural circuitry involved. The specific aims are to: 1) determine mechanisms by which sss regulates Sh, 2) determine the role of RNA-editing of sss in modulation of sleep and Sh currents, and 3) determine where in the brain sss acts to regulate sleep. Collectively these studies will improve our understanding of the molecular basis of sleep need and how it leads to major changes in electrical activity in the brain. Such findings may also help identify new targets for intervening both in disorders of sleep and in disorders related to misregulation of neuronal excitability in general.

描述(申请人提供)：睡眠是一个基本的、进化上保守的过程，如果不能完成，就会导致人类病理。睡眠的重要性通过其严格的体内平衡控制得到了强调：睡眠动力随着清醒时间的增加而增加，随着睡眠时间的推移而消散。然而，睡眠调节的分子机制和控制睡眠稳态的神经电路在很大程度上是未知的。事实证明，果蝇在识别与行为、人类健康和疾病相关的基因方面很有用，它也成为研究睡眠的一个有价值的遗传模型系统。使用正向基因筛查，我们确定了睡眠剥夺后基线和稳态恢复睡眠所需的新基因无眠(Sss)。在sss突变体中，我们发现睡眠调节K通道Shaker(Sh)的水平降低，从而导致sss夫妇睡眠驱动膜兴奋性降低的假说。最近，我们还发现，除了调节Sh电流的幅度和动力学外，Sss还可以调节Sh通道的局部化。与SSS对Sh的直接调控一致，我们证明了Sh的表达是通过通道和SSS之间形成稳定的复合体而在转录后促进的。SSS处于RNA编辑机制的控制之下，编辑后的SSS在促进睡眠方面不如不可编辑的SSS有效。因此，我们假设RNA编辑控制SSS与Sh相互作用的能力，从而改变通道的活动和亚细胞运输。SSS-Sh相互作用的结构基础特别耐人寻味：SSS是一大家族的创始成员之一，这些蛋白质的特征相对较差，类似于神经毒素，通常作用于离子通道，这增加了该家族的其他成员可能调节兴奋性和睡眠的可能性。这一建议的重点是确定SSs调节睡眠的分子基础，特别是关于Sh的分子基础，并描述涉及的神经回路。其具体目的是：1)确定SSs调节Sh的机制，2)确定SSs的RNA编辑在调节睡眠和Sh电流中的作用，以及3)确定SSs在大脑中的什么位置调节睡眠。总的来说，这些研究将提高我们对睡眠需求的分子基础的理解，以及睡眠需求如何导致大脑电活动的重大变化。这些发现还可能有助于确定新的干预目标，既可以干预睡眠障碍，也可以干预与神经元兴奋性失调有关的障碍。