Genetic Regulation of Peptidergic Signaling

肽能信号传导的基因调控

• 批准号: 0344018
• 负责人: Randall Hewes
• 金额: $ 35.18万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0344018&HistoricalAwards=false
• 关键词: Genetic; Regulation; Peptidergic; Signaling

Neuropeptides are chemical signals that are secreted by nerve cells to control the functioning of the brain and many other tissues. They are key regulators of diverse processes, including growth, reproduction, stress, sleep, body weight, pain, and circadian (daily) rhythms. Disruptions in neuropeptide signaling are associated with human diseases, such as obesity, diabetes and cancer. Thus, there is a critical need for basic research on neuropeptide systems. The major goal of this project is to understand complex molecular mechanisms underlying long-term regulation of neuropeptide secretion. To support normal signaling, peptidergic (neuropeptide-secreting) cells must develop the capacity to produce and store large quantities of neuropeptides. In mature cells, neuropeptide synthesis is regulated in response to diverse internal and external cues in order to adjust the strength of neuropeptide signaling. For many cell types, the genes and cell signaling pathways underlying these processes, and their physiological and developmental regulation, are almost completely unknown. With the powerful tools recently developed for the genetic manipulation of peptidergic cells in the fruit fly, Drosophila melanogaster, these mechanisms are now experimentally accessible. In previous work, the Drosophila gene dimmed (dimm) was shown to control accumulation and/or storage of secretory proteins in diverse peptidergic cells. This result suggests that dimm is an essential component of a cell signaling pathway controlling the robustness and timing of neuropeptide synthesis. To test this hypothesis, this project will address two key questions. First, what are the roles of dimm in developing versus mature cells? Second, what other proteins interact with Dimm, the protein product of the dimm gene, to control neuropeptide levels? To address the first question-what are the roles of dimm in developing versus mature cells-the first aim of this project is to define the contributions of the dimm gene in the regulation or maintenance of neuropeptide synthesis throughout the life cycle of the fly. Using transgenic animals, and a new temperature-dependent gene expression system, a re-introduced copy of the dimm gene will be turned on or off during specific stages of development. This system also allows peptidergic cell-type specific control over the expression of the dimm gene. Thus, transient and spatially restricted expression of the dimm gene will be used to determine the effects of post-embryonic increases in dimm expression on neuropeptide levels in dimm mutant and in normal cells. To address the second question-what other proteins interact with Dimm to control neuropeptide levels-the second aim of this project is to perform genetic screens to identify mutations of genes encoding other elements in the Dimm molecular signaling pathway. Genes will be identified by virtue of their ability to modify the effects of dimm misexpression in transgenic animals. Genetic interactions will be detected using two dimm-sensitive processes: molting and neuropeptide synthesis. Selected mutants then will be tested for effects on neuropeptide levels in developing and mature cells, and the mutated genes will be identified using standard Drosophila molecular cloning methods. Together, the proposed experiments will lay a foundation for defining key molecular pathways controlling neuroendocrine signaling.This project will continue to provide unique opportunities for several undergraduate and graduate students to participate in the research. Students in Oklahoma have few options for non-agricultural training in the sciences. This project provides hands-on experiences in molecular biology and genetics that are not otherwise readily available and that complement traditional lecture-format courses. These research experiences will continue to enable and inspire talented students from the State of Oklahoma to pursue professional careers in industry, medicine, and scientific research.

神经肽是神经细胞分泌的化学信号，以控制大脑和许多其他组织的功能。 它们是各种过程的关键调节因子，包括生长，繁殖，压力，睡眠，体重，疼痛和昼夜节律（每日）节奏。 神经肽信号传导的破坏与肥胖，糖尿病和癌症等人类疾病有关。 因此，对神经肽系统的基础研究非常需要。 该项目的主要目的是了解神经肽分泌长期调节的复杂分子机制。为了支持正常的信号传导，肽能（神经肽分泌）细胞必须发展产生和存储大量神经肽的能力。 在成熟的细胞中，神经肽的合成受到多种内部和外部线索的响应，以调节神经肽信号传导的强度。 对于许多细胞类型，这些过程及其生理和发育调控的基因和细胞信号通路几乎完全未知。 借助最近开发了用于果蝇果蝇中肽基细胞的遗传操纵的工具，这些机制现在可以在实验上访问。 在先前的工作中，果蝇基因昏暗（DIMM）可控制分泌蛋白在各种肽吉尼细胞中的积累和/或储存。 该结果表明DIMM是控制神经肽合成的鲁棒性和时机的细胞信号通路的重要组成部分。 为了检验这一假设，该项目将解决两个关键问题。 首先，DIMM在发展与成熟细胞中的作用是什么？ 其次，哪些其他蛋白质与DIMM（DIMM基因的蛋白质产物）相互作用，以控制神经肽水平？ 要解决第一个问题 - DIMM在开发与成熟细胞中的作用是什么 - 该项目的第一个目的是定义DIMM基因在整个苍蝇生命周期中神经肽合成的调节或维持中的贡献。 使用转基因动物和新的温度依赖性基因表达系统，在发育的特定阶段，将打开或关闭DIMM基因的重新引入的副本。 该系统还允许对DIMM基因表达的肽吉尼细胞类型的特异性控制。 因此，将使用DIMM基因的瞬时和空间限制表达来确定DIMM表达对DIMM突变体和正常细胞中神经肽水平的增加的影响。 为了解决第二个问题 - 其他蛋白质与DIMM相互作用以控制神经肽水平 - 该项目的第二个目的是执行遗传筛选，以识别编码DIMM分子信号通路中其他元素的基因突变。 基因将通过其修改DIMM Misexpression在转基因动物中的影响的能力来识别基因。 将使用两个DIMM敏感的过程检测遗传相互作用：摩托学和神经肽合成。 然后，将测试选定的突变体对发育和成熟细胞中神经肽水平的影响，并使用标准果蝇分子克隆方法鉴定突变的基因。 拟议的实验将共同定义控制神经内分泌信号的关键分子途径的基础。该项目将继续为几位本科生和研究生提供参与研究的独特机会。 俄克拉荷马州的学生在科学领域的非农业培训方面几乎没有选择。 该项目提供了分子生物学和遗传学方面的动手经验，这些经验并不容易获得，并补充了传统的讲座格式课程。 这些研究经验将继续使俄克拉荷马州的才华横溢的学生能够从事行业，医学和科学研究。