Roles of a novel immunoglobulin-domain protein in sleep and circadian behavior

新型免疫球蛋白结构域蛋白在睡眠和昼夜节律行为中的作用

• 批准号: 9095569
• 负责人: F Rob JACKSON
• 金额: $ 24.75万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9095569
• 关键词: Adult; Affect; Amino Acids; Animals; Antibodies; Area; Arousal; Behavior; Brain; CRISPR/Cas technology; Caenorhabditis elegans; Cells; Circadian Rhythms; Drosophila genus; Drosophila melanogaster; Elements; Exhibits; Genes; Genetic; Genetic Epistasis; Genetic Screening; Homologous Protein; Hormones; Human; Immune Sera; Immunoglobulin Domain; Immunoglobulins; Injury; Insecta; Mammals; Mediating; Mediator of activation protein; Molecular; Molecular Profiling; Mutation; Names; Nervous system structure; Neurohormones; Neurons; Neuropeptides; Pacemakers; Pathway interactions; Pattern; Peptide Signal Sequences; Peptides; Phenotype; Phosphorylation; Physiological; Pigments; Population; Protein Isoforms; Proteins; RNA Interference; Regulation; Reporter; Research; Role; Signal Transduction; Signaling Molecule; Sleep; Testing; Tissues; Transgenes; Transgenic Organisms; Vasoactive Intestinal Peptide; Vasoactive Intestinal Peptide Receptors; Work; awake; base; cell type; circadian pacemaker; fly; insight; knock-down; knowledge base; melanin-concentrating hormone; mutant; nervous system development; nervous system disorder; neuregulin 2; neurodevelopment; neuronal circuitry; neurotransmission; novel; peptide hormone; protein function; public health relevance; receptor; release factor; research study; sleep regulation; suprachiasmatic nucleus; synaptogenesis

 DESCRIPTION (provided by applicant): In mammals and insects, intercellular signaling by peptides and protein hormones is critical for the functions of circuits regulating sleep and circadian behavior. In this application, we propose experiments to test the hypothesis that neuronal secretion and action of a novel immunoglobulin (Ig)-domain protein is required for proper function of the Drosophila circadian and sleep circuits. Ig superfamily molecules are important mediators of neural development, synapse formation, plasticity and injury (1;2), although less is known about the adult functions for these proteins. In recent expression profiling studies, we identified numerous Drosophila Ig protein-encoding genes that are expressed in the adult brain. Sixteen of them, including the CG141441 (Nkt) gene, have high adult nervous system expression and encode Ig proteins that are predicted to be secreted molecules. (FlyAtlas; (3)). In unpublished studies, we have shown that flies with RNAi-generated pan-neuronal deficits for Nkt exhibit reduced nighttime sleep and lengthened circadian period. Selective knockdown of Nkt in clock neurons causes a lengthened circadian period with no effect on sleep. These results suggest that Nkt is required in different neuronal cell types for th regulation of sleep and circadian behavior. Interestingly, genetic interaction with a period (pers) mutation suggests that NKT acts on pacemaker neurons and through the molecular clock to regulate circadian period. As NKT is predicted to be a small secreted Ig protein, we hypothesize that it serves a signaling function, similar to PDF neuropeptide, in the circadian circuit. In this R21 application, we propose to study the functions of NKT in the regulation of adult rhythmic behavior and sleep. Aim 1 will use conditional expression approaches to verify that NKT protein has a physiological requirement in the adult brain for the regulation of behavior. Additionally, it will delineate the neuronal requirements for the protein in sleep and circadian behavior. Aim 2 will examine genetic interactions with clock and sleep-altering mutations to better understand NKT's mechanistic functions in the relevant neuronal circuits. This aim will also ask whether NKT is secreted from neurons and test the hypothesis that the Ig protein is required for molecular oscillator function or synchronization of the clock neuron population. Proteins homologous to NKT, with single immunoglobulin domains are present in many species including C. elegans, Drosophila and humans (e.g., small secreted Neuregulin-2 isoforms). Thus, the research is likely to provide novel insights about signaling mechanisms that function in the differentiated brain.

 描述（由申请人提供）：在哺乳动物和昆虫中，肽和蛋白质激素的细胞间信号传导对于调节睡眠和昼夜行为的回路功能至关重要。在此应用中，我们提出的实验来测试的假设，神经元分泌和行动的一种新的免疫球蛋白（IG）结构域蛋白是必需的果蝇昼夜节律和睡眠电路的正常功能。IG超家族分子是神经发育、突触形成、可塑性和损伤的重要介质（1;2），尽管对这些蛋白质的成人功能知之甚少。在最近的表达谱研究中，我们确定了许多果蝇IG蛋白编码基因，在成人大脑中表达。其中包括CG 141441（Nkt）基因在内的16个基因在成人神经系统中具有高表达，并编码预测为分泌分子的IG蛋白。（FlyAtlas;（3））。在未发表的研究中，我们已经表明，具有RNAi产生的Nkt泛神经元缺陷的果蝇表现出夜间睡眠减少和昼夜节律周期延长。选择性敲低时钟神经元中的Nkt会导致昼夜节律周期延长，但对睡眠没有影响。这些结果表明，Nkt是需要在不同的神经元细胞类型的睡眠和昼夜行为的th调节。有趣的是，与周期（pers）的遗传相互作用 突变提示NKT作用于起搏神经元，通过分子钟调节昼夜节律。由于NKT被预测为一种小的分泌型IG蛋白，我们假设它在昼夜节律回路中具有类似于PDF神经肽的信号传导功能。在这 R21的应用，我们建议研究NKT在成年节律行为和睡眠调节中的功能。目的1利用条件表达技术验证NKT蛋白在成年人大脑中对行为调控的生理需求。而且 将描绘睡眠和昼夜行为中神经元对蛋白质的需求。目标2将研究与生物钟和睡眠改变突变的遗传相互作用，以更好地了解NKT在相关神经元回路中的机械功能。该目标还将询问NKT是否从神经元分泌，并检验IG蛋白是分子振荡器功能或时钟神经元群体同步所需的假设。与NKT同源的蛋白质，具有单个免疫球蛋白结构域，存在于许多物种中，包括C。线虫、果蝇和人类（例如，小分泌的神经调节蛋白-2同种型）。因此，这项研究可能会提供有关在分化的大脑中发挥作用的信号机制的新见解。