G PROTEIN SIGNALING IN THE C ELEGANS NERVOUS SYSTEM

本提案的长期目标是了解如何 神经递质通过G蛋白偶联受体起作用， 神经元的活动。 我们的研究集中在一种神经递质 调节神经元和肌肉活动的信号通路 对C.优雅我们已经发现了突变 扰乱了产卵行为的调节， 鉴定和研究编码这种G蛋白信号传导成分的基因 通路 到目前为止，所分析的基因具有表达在细胞中的密切同源物。 哺乳动物脑，表明C. elegans将被证明是一个有用的模型 来理解人类通过G蛋白的神经传递。 该提案的第一个主要目标是系统地利用 我们开发了一个分子遗传学系统来分析这个 神经递质信号通路 我们将进行饱和 基因筛选以尽可能多地识别信号基因。 我们将克隆并对这些基因进行分子分析。我们的目标是 最终降低了我们对G蛋白信号通路的理解 到生物化学水平。 这种方法的潜力体现在以下事实上： 已经用它来鉴定一种蛋白质，EGL-10，它抑制信号传导 C.中的异三聚体G蛋白。线虫产卵系统 EGL-10是一个大家族的蛋白质的原型，我们发现， 我们称之为“G蛋白调节器 信号传导”（RGS）蛋白。 这些RGS蛋白可能调节可能或全部 G蛋白信号通路。 这项建议的第二个主要目的是确定为什么会有这样的情况， 许多RGS蛋白。 它们只是多余的，还是每一个都有一个 特定的生物功能，也许是因为每一个都局限于 与特定的G蛋白或一组G蛋白相互作用？ 我们将 通过确定遗传功能和表达来研究这个问题， 11种蠕虫RGS蛋白的模式，并通过研究生物化学 C.线虫RGS和G蛋白 体外 这种分析应该揭示家庭的逻辑， RGS蛋白调节蠕虫中的多种信号通路。 因为 许多C。线虫G蛋白和RGS蛋白与 相应的人类同源物，我们的分析应该阐明 类似的人类信号通路，并指导他们的进一步研究。

The long-term goal of this proposal is to understand how neurotransmitters act through G protein-coupled receptors to modulate the activities of neurons. Our studies focus on a neurotransmitter signaling pathway that regulates activities of the neurons and muscles of the egg-laying system of C. elegans. We have identified mutations that disrupt the regulation of egg-laying behavior and used them to identify and study genes encoding components of this G protein signaling pathway. The genes analyzed so far have close homologs expressed in the mammalian brain, suggesting that C. elegans will prove a useful model for understanding neurotransmission through G proteins in humans. The first major aim of this proposal is to systematically exploit the molecular genetic system we have developed to analyze this neurotransmitter signaling pathway. We will carry out saturating genetic screens to identify as many of the signaling genes as possible. We will clone and molecularly analyze these genes. Our goal is to eventually reduce our understanding of this G protein signaling pathway to a biochemical level. The potential of this approach is illustrated by the fact that we have already used it to identify a protein, EGL-10, that inhibits signaling by a heterotrimeric G protein in the C. elegans egg-laying system. EGL-10 is a prototype for a large family of proteins we identified in worms and humans that we have named the "regulator of G protein signaling" (RGS) proteins. These RGS proteins may regulate may or all G protein signaling pathways. The second major aim of this proposal is to determine why there are so many RGS proteins. Are they simply redundant, or does each have a specific biological function, perhaps because each is restricted to interacting with a particular G protein or set of G proteins? We will examine this issue by determining the genetic functions and expression patterns of the 11 worm RGS proteins and by studying the biochemical specificity of the interactions between C. elegans RGS and G proteins in vitro. this analysis should reveal the logic by which the family of RGS proteins regulates multiple signaling pathways in the worm. Because many C. elegans G proteins and RGS proteins are closely related to corresponding human homologs, our analysis should shed light on analogous human signaling pathways and direct their further study.