SIGNALING PROCESSES IN DICTYOSTELIUM

盘基网菌中的信号传导过程

• 批准号: 2179000
• 负责人: RICHARD A FIRTEL
• 金额: $ 38.87万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-07-01 至 1995-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2179000
• 关键词: DNA footprinting; Dictyostelium; Escherichia coli; G protein; adenylate cyclase; affinity chromatography; antibody; biological signal transduction; cell aggregation; cell differentiation; cell motility; cell transformation; chemotaxis; chimeric proteins; cyclic AMP; cyclic AMP receptors; developmental genetics; electroporation; epitope mapping; fusion gene; gene expression; gene mutation; genetic library; genetic regulatory element; genetic transcription; guanylate cyclase; histogenesis; hydrolase; immunofluorescence technique; laboratory mouse; laboratory rabbit; microorganism genetics; molecular cloning; molecular genetics; oncogenes; phospholipase C; phosphorylation; phosphotransferases; posttranslational modifications; protein purification; protein structure function; temperature sensitive mutant; transcription factor; western blottings

Development in the cellular slime mold Dictyostelium discoideum is regulated in part by extracellular molecules that interact with cell surface receptors. This application is directed at understanding the molecular and biochemical mechanisms by which signal transduction pathways control both cellular morphogenesis and gene expression during the pre-aggregation and aggregation stages of development. Using molecular techniques, we have identified and cloned genes whose products are essential in controlling this and other stages of development. These include genes encoding four G alpha protein subunits, each with a distinct developmental pattern of expression, a developmentally regulated phosphotyrosine phosphatase, and developmentally regulated putative serine/threonine kinases. Gene disruptions and overexpression studies have indicated that the proteins encoded by each of these genes play essential roles in development. Our analysis indicates that G alpha2 couples to the cAMP receptor cARI and regulates diverse signal transduction pathways that mediate chemotaxis during aggregation and the induction of pulse-induced genes. In this application, we propose to dissect the signal transduction pathways regulated by these proteins using molecular techniques to produce appropriate strains that either do not express the proteins or express modified proteins. In vitro analysis will be used to characterize the effects of the mutations at a biochemical level. Using molecular complementation, we propose to isolate additional genes in the signaling pathways that have been previously identified by in vivo mutations. We will also continue to characterize the function of the cell-type-specific ras gene within the signal transduction pathway. In order to understand the molecular basis of receptor-mediated control of gene expression during aggregation, we plan to further identify the cis-acting regulatory regions of genes regulated by cAMP pulses and to purify the regulatory trans-acting factors that mediate the response at the level of transcription.

细胞粘液模具dictyostelium discoideum中的发展是 部分由与细胞相互作用的细胞外分子调节 表面受体。 该应用程序旨在了解 信号转导的分子和生化机制 途径控制细胞形态发生和基因表达 发展前的聚集和聚合阶段。使用 分子技术，我们已经鉴定了和克隆的基因 对于控制这一发展阶段和其他阶段至关重要。这些 包括编码四个Gα蛋白亚基的基因 独特的表达发展模式，一种受发展调节的 磷酸酪氨酸磷酸酶和发育调节的推定 丝氨酸/苏氨酸激酶。 基因破坏和过表达研究 已经表明，这些基因中每个基因编码的蛋白质 在发展中的基本作用。 我们的分析表明g alpha2 伴侣到营受体Cari并调节多样的信号 在聚集过程中介导趋化性的转导途径和 诱导脉冲诱导的基因。 在此应用中，我们建议剖析信号转导 由这些蛋白质调节的途径使用分子技术 产生适当的菌株，即不表达蛋白质或 明确修饰的蛋白质。 体外分析将用于 表征生化水平突变的作用。 使用 分子互补，我们提议分离出其他基因 先前由体内识别的信号通路 突变。 我们还将继续表征 信号转导途径内的细胞型特异性RAS基因。 在 为了了解受体介导的对照的分子基础 汇总过程中的基因表达，我们计划进一步识别 由营地脉冲调节的基因的顺式作用调节区域 净化调解介导的调节性跨作用因子 转录水平。