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REGULATION OF DEVELOPMENT BY PHOSPHORELAY SIGNALING

通过磷传递信号调节发育

基本信息

批准号：
6525523
负责人：
CHARLES K SINGLETON
金额：
$ 24.52万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-08-01 至 2004-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6525523
关键词：
Dictyostelium biological signal transduction cell growth regulation cyclic AMP enzyme activity eukaryote gene expression gene mutation growth inhibitors molecular cloning phosphomonoesterases phosphorylation polymerase chain reaction protein kinase A

项目摘要

During development, cells must make choices between alternative pathways, and they must maintain appropriate developmental timing so that differentiation and morphogenesis are coordinated. This is accomplished by an assessment of the cell's environment through sensory signal transduction mechanisms and integration of the relevant extracellular and intracellular information to allow the appropriate decision to be made and timing to be maintained. Recent genetic evidence suggests that the major signaling mechanism of prokaryotes couples to a major eukaryotic effector to regulate the timing of multicellular development and choices between alternative developmental pathways and cell fates in Dictyostelium. We hypothesize that a two-component phosphorelay, controlled by sensory histidine kinases DHKC and DHKB, regulate these important aspects of development by modulating the activity of cAMP-dependent protein kinase. Molecular genetic and biochemical approaches are proposed that will establish the molecular mechanisms that result in the regulation and control of multicellular development. Specifically, experiments in vivo and in vitro will examine the biochemical details of the phosphorelay by characterizing the autophosphorylation, phosphatase, and phosphotransfer activities of the various components and by determining the effects of one component on the activities of the others. Ectopic expression of stimulus-independent activators or inhibitors of the pathway, using cell type-specific promoters, will reveal in which cell type(s) the pathway functions and if the pathway results in cell to cell signaling to couple differentiation and morphogenesis. Finally genetic screens for suppressers or synthetic phenotypes will identify new and perhaps novel components of the regulatory pathway, including upstream inputs, phosphorelay regulators, and downstream effectors.

在发育过程中，细胞必须在替代途径之间做出选择，它们必须保持适当的发育时机，以便协调分化和形态发生。这是通过感官信号转导机制和相关细胞外和细胞内信息的整合来评估细胞环境，以允许做出适当的决定并维持时机来实现的。最近的遗传学证据表明，原核生物的主要信号传导机制耦合到一个主要的真核生物效应器，以调节多细胞发育的时间和替代发育途径和细胞命运之间的选择在网骨藻。我们推测，一个双组分的磷酸化继电器，控制的感觉组氨酸激酶DHKC和DHKB，调节这些重要方面的发展，通过调节cAMP依赖性蛋白激酶的活性。分子遗传学和生物化学的方法提出，将建立分子机制，导致多细胞发育的调控。具体而言，在体内和体外实验将检查的生化细节的磷酸化，磷酸酶，磷酸转移活动的各种组件的特征，并通过确定一个组件上的其他活动的影响。使用细胞类型特异性启动子的途径的刺激非依赖性激活剂或抑制剂的异位表达将揭示途径在哪种细胞类型中起作用以及途径是否导致细胞间信号传导以偶联分化和形态发生。最后，基因筛选抑制或合成表型将确定新的，也许是新的组件的监管途径，包括上游输入，磷酸化调节器，和下游效应。