G Protein Modulation of Glycine Receptor Function and Ethanol Action

G 蛋白对甘氨酸受体功能和乙醇作用的调节

• 批准号: 7893837
• 负责人: Gregg E. Homanics
• 金额: $ 3.82万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-12 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7893837
• 关键词: Acute; Affect; Affinity; Agonist; Alcohol consumption; Alcoholic Intoxication; Alcohols; Animal Behavior; Animals; Basic Amino Acids; Behavior; Behavior Control; Behavioral; Brain Stem; Chemosensitization; Chronic; Data; Dependence; Engineering; Ethanol; Exposure to; GTP-Binding Proteins; Gene Targeting; General anesthetic drugs; Genes; Genetically Engineered Mouse; Glycine; Glycine Receptors; In Situ; Knowledge; Laboratories; Mediating; Mus; Mutant Strains Mice; Mutate; Mutation; Neurons; Pain; Perception; Physiological; Play; Principal Investigator; Property; Proteins; RNA; Recombinants; Research; Resistance; Respiration; Rodent; Role; Sensory; Spinal; Spinal Cord; System; Testing; Work; clinically relevant; dimer; drinking behavior; embryonic stem cell; hypoglossal nucleus; motor control; mutant; neuronal excitability; novel; protein activation; receptor; receptor function; response; stem cell technology

DESCRIPTION (provided by applicant): Glycine receptors (GlyRs) play a critical role in neuronal excitability in the mammalian brain stem and spinal cord. Their activation reduces the excitability of neurons associated with sensory information, motor control and respiration, functions that are significantly altered during ethanol (EtOH) intoxication. Studies from our and other laboratories demonstrated that the glycine-activated Cl current can be potentiated by low, clinically relevant EtOH concentrations in native neurons and heterologous expression systems. Studies by Aguayo and others have revealed a novel mechanism of EtOH action on GlyRs that involves modulation by G protein activation. We (Aguayo) recently demonstrated that GlyRs are modulated by G protein ?? subunits via basic residue domains within the TM3-4 intracellular loop of a1-containing GlyRs. Importantly, our preliminary results showed that mutants resistant to G??? dimer modulation were insensitive to potentiation by EtOH. Noteworthy, other receptor properties (apparent agonist and antagonist affinities and single channel conductance) were normal and receptor modulation by general anesthetics was not altered, indicating significant selectivity for EtOH. Altogether, these data demonstrate that basic amino acids in the large intracellular loop regulate the sensitivity of GlyRs to physiologically relevant concentrations of EtOH. However, the prime question that has not yet been answered is: What is the importance of G??? modulation of GlyR function in terms of expression of the clinically relevant effects of EtOH exposure on whole animal behavior? To fill this gap in our knowledge, we propose to extend the pioneering studies of Aguayo to the whole animal level. Our working hypothesis is that EtOH affects GlyR function by free G??? through specific regions in the intracellular loop, and that G??? modulation of GlyRs is critical for the behavioral effects of EtOH. Our primary objectives are to generate gene knockin mice that harbor mutant a1 GlyRs that are insensitive to modulation by G???, and test these mice for cellular and behavioral responses to EtOH.

描述（由申请人提供）：甘氨酸受体（Glyrs）在哺乳动物脑干和脊髓中神经元兴奋性中起关键作用。它们的激活降低了与感觉信息，运动控制和呼吸相关的神经元的兴奋性，这些功能在乙醇（ETOH）中毒过程中发生了显着改变。来自我们和其他实验室的研究表明，甘氨酸激活的CL电流可以通过天然神经元和异源表达系统的低临床相关ETOH浓度来增强。 Aguayo和其他人的研究揭示了ETOH作用在Glyrs上的新型机制，涉及G蛋白激活调节。我们（Aguayo）最近证明了Glyrs是由G蛋白调节的？通过基本残基域的亚基在含A1的Glyrs的TM3-4细胞内环内。重要的是，我们的初步结果表明，突变体对G？二聚体调制对ETOH的增强不敏感。值得注意的是，其他受体特性（明显的激动剂和拮抗剂亲和力以及单个通道电导率）是正常的，并且通过通用麻醉剂调节受体调节没有改变，表明ETOH的显着选择性。总的来说，这些数据表明，大细胞内环中的碱性氨基酸调节Glyrs对生理相关浓度的ETOH的敏感性。但是，尚未回答的主要问题是：G的重要性是什么？在表达ETOH暴露对整个动物行为的临床相关作用方面，Glyr功能的调节？为了填补我们的知识，我们建议将Aguayo的开创性研究扩展到整个动物水平。我们的工作假设是ETOH会通过自由g影响Glyr功能？？？通过细胞内环中的特定区域以及G ??? Glyrs的调节对于ETOH的行为效应至关重要。我们的主要目的是生成具有对G ???不敏感的突变体A1 Glyrs的基因敲击蛋白小鼠，并测试这些小鼠对ETOH的细胞和行为反应。