Heterotrimeric G-protein regulation of neurotransmission in C. elegans

异源三聚体 G 蛋白对线虫神经传递的调节

• 批准号: 7556778
• 负责人: Kevin Michael Collins
• 金额: $ 5.01万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7556778
• 关键词: 1,2-diacylglycerol; Adult; Affect; Anabolism; Animal Feed; Behavior; Biochemical; Biological; Biological Assay; Brain; Caenorhabditis elegans; Cell division; Cells; Diglycerides; Embryo; Endocytosis; Enzymes; Eukaryota; Exocytosis; Family member; Frequencies; G-Protein-Coupled Receptors; GTP-Binding Proteins; Gene Expression; Genes; Genetic; Genetic Screening; Genetic Transcription; Guanosine Triphosphate Phosphohydrolases; Heterotrimeric GTP-Binding Proteins; Human; Hydrolysis; Imagery; In Situ; Inositol; Ion Channel; Light; Maps; Microarray Analysis; Microtubules; Mitotic; Mitotic spindle; Molecular; Molecular Profiling; Muscle Contraction; Muscle Tremors; Mutation; Nematoda; Nervous system structure; Neurodegenerative Disorders; Neurons; Parkinson Disease; Perception; Pharmacologic Substance; Phenotype; Phosphatidylinositols; Phospholipase C; Phospholipids; Positioning Attribute; Protein Biosynthesis; Regulation; Research; Second Messenger Systems; Seizures; Sensory; Serotonin; Signal Pathway; Signal Transduction; Soil; Suppressor Mutations; Synapses; Synaptic Vesicles; Syndrome; Testing; Transducers; Tryptophan 5-monooxygenase; base; cell growth; cell motility; egg; in vivo; member; mutant; neurotransmission; novel; receptor; research study; response; second messenger; sensor; tripolyphosphate

Signaling through heterotrimeric GTPases (G-proteins) activates cellular effector enzymes and ion channels to regulate cell growth, mitotic division, and sensory perception. G-protein coupled receptors are among the most commonly used signal transducers in eukaryotes and are the targets of about half of prescribed Pharmaceuticals. The soil nematode, Caenorhabditis elegans, offers many experimental advantages to investigate the conserved features of heterotrimeric G-protein signaling. In embryos, G- proteins regulate microtubule forces that control mitotic spindle positioning during asymmetric cell division. In adults, G-proteins coordinate animal feeding, motility, and other behaviors by altering synaptic activity and the frequency of muscle contractions. These behaviors offer convenient and quantitative assays to study intracellular and intercellular signaling genetically. Through three independent lines of experimentation, I will study the molecular and cellular consequences of signaling through two G-proteins, EGL-30 (Gctq) and GOA-1 (Ga0). Activated EGL-30 interacts with EGL- 8, the phosphatidylinositol (4,5) bisphosphate (PlPz)-specific Phospholipase C (p) family member. Hydrolysis of PIP? by EGL-8 releases the second messengers inositol 1,4,5-triphosphate (IP3) and 1,2- diacylglycerol (DAG). In contrast, direct effectors of activated GOA-1 remain unknown. To find these, I will isolate mutants that suppress hyperactivated GOA-1 signaling phenotypes. One suppressor has already been mapped by members of the Koelle lab, and I will map additional suppressor mutations, determine how the encoded factors regulate signaling, and test whether they act as direct effectors for GOA-1. Second, to study how GOA-1 antagonizes EGL-30 signaling to modulate synaptic activity, I will visualize EGL-8 activity in vivo using established fluorescent sensors of Ca+2 and specific phospholipids. I will test how mutations that impair or stimulate inhibitory GOA-1 signaling affect the behavior and distribution of these indicators. These in situ biochemical experiments will reveal the cell biological consequences of the signaling pathways defined genetically. Finally, to find genes whose expression is regulated by signaling, I will compare gene expression profiles in goa-1 and egl-30 mutants by microarrayanalysis. This research will shed light on how the nervous system controls the frequency of muscle contractions. As these functions are perturbed during human brain seizures, muscle tremors, and neurodegenerative diseases such as Parkinson's, these studies should inform a rational basis for targeted therapies.

通过异三聚体GTPase（G蛋白）信号传导激活细胞效应酶和离子 调节细胞生长，有丝分裂分裂和感觉知觉的通道。 G蛋白偶联受体是 在真核生物中最常用的信号传感器中，是大约一半的目标 处方药。土壤线虫，秀丽隐杆线虫，提供许多实验性 研究异三聚体G蛋白信号传导的保守特征的优势。在胚胎中，g- 蛋白质调节在非对称细胞分裂过程中控制有丝分裂纺锤体定位的微管力。 在成年人中，G蛋白通过改变突触活动和 肌肉收缩的频率。这些行为提供了方便和定量的测定 细胞内和细胞间信号在遗传上。 通过三个独立的实验线，我将研究分子和细胞后果 通过两个G蛋白EGL-30（GCTQ）和GOA-1（GA0）信号传导。激活的EGL-30与EGL-相互作用 8，磷脂酰肌醇（4,5）双磷酸（PLPZ）特异性磷脂酶C（P）家族成员。 PIP的水解？通过EGL-8释放第二章肌醇1,4,5-三磷酸（IP3）和1,2-- 二酰基甘油（DAG）。相比之下，活化的果阿-1的直接效应子仍然未知。为了找到这些，我会 抑制过度活化的果阿-1信号表型的分离物突变体。一个抑制器已经 由Koelle实验室成员绘制，我将绘制其他抑制剂突变，确定如何 编码的因素调节信号传导，并测试它们是否充当果阿-1的直接效应子。第二，到 研究GOA-1如何拮抗EGL-30信号传导以调节突触活动，我将可视化EGL-8活动 使用CA+2的荧光传感器和特定的磷脂。我将测试突变 这种损害或刺激抑制性GOA-1信号会影响这些指标的行为和分布。 这些原位生化实验将揭示信号传导途径的细胞生物学后果 遗传上定义。最后，为了找到表达受信号调节的基因，我将比较基因 通过微阶层分析中果阿-1和EGL-30突变体中的表达谱。 这项研究将阐明神经系统如何控制肌肉收缩的频率。 由于这些功能在人脑癫痫发作期间受到干扰，肌肉震颤和神经退行性 帕金森（Parkinson's）等疾病，这些研究应为有针对性疗法的合理基础提供理性的基础。