MAP kinase regulation of cell-fate transitions in yeast

MAP 激酶对酵母细胞命运转变的调节

• 批准号: 7995234
• 负责人: BEVERLY ERREDE
• 金额: $ 30.07万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7995234
• 关键词: Affect; Attenuated; Binding; Bioinformatics; Biological; Cell Fate Control; Cell physiology; Cells; Commit; Computer Simulation; DNA; Data; Data Set; Development; Disease; Dose; Feedback; Gene Expression; Genes; Genetic; Genetic Models; Genetic Programming; Genetic Transcription; Global Change; Growth; Health; Hepatocyte; Homeostasis; Hormones; Human; Image; Individual; Inflammatory; Label; Lead; Learning; Life; Location; Malignant Neoplasms; Maps; Measurement; Mediating; Messenger RNA; Metabolic Diseases; Methodology; Microarray Analysis; Microfluidic Microchips; Mitogen-Activated Protein Kinases; Modeling; Molecular; Molecular Profiling; Monitor; Mutation; Non-Insulin-Dependent Diabetes Mellitus; Organism; Outcome; Partner in relationship; Pathogenesis; Pathway interactions; Pattern; Pheromone; Physiological; Plant Roots; Proteins; Proteomics; RNA; Regulation; Regulatory Pathway; Relative (related person); Resistance; Role; Saccharomyces cerevisiae; Saccharomycetales; Signal Pathway; Signal Transduction; Specific qualifier value; Stimulus; System; Testing; Time; To specify; Transcription Repressor/Corepressor; Translating; Validation; Variant; Yeasts; base; bone cell; brain cell; cell type; cellular development; dosage; genetic manipulation; genome-wide; insight; interdisciplinary approach; mathematical model; model development; mutant; programs; promoter; response; time interval; transcription factor

DESCRIPTION (provided by applicant): Mechanisms that coordinate transcriptional programs in response to specific stimuli are central to understanding normal development and homeostasis. The pheromone-induced transition of budding yeast to either a chemotrophic or mating competent form is a model for dissecting the molecular basis of this regulation. A single mitogen activated protein kinase (MAPK) cascade mediates both transitions. This pathway utilizes two MAPKs, Fus3 and Kss1, that both negatively and positively regulate activity of the Ste12 and Tec1 transcriptional regulators. Ste12 is essential for the changes in gene expression that underlie establishment of both fates while Tec1 is important only for the chemotrophic fate. The genetic program for the chemotrophic fate transition induced by low pheromone concentration is still undefined. Fus3 and Kss1 activation profiles are differentially affected at high vs. low pheromone. We hypothesize that the dose-dependent differences in their activation and their antagonistic regulatory roles control Ste12 and Tec1 activity and degradation in a manner that prepares cells for one or the other differentiation program. We propose a multidisciplinary approach to compare the regulatory networks for the two fates and the molecular basis of the developmental switch: Aim 1. Define the global expression program for chemotrophic growth using microarray technology and compare it to that for mating differentiation. Bioinformatic approaches are proposed to delineate the physiological and phenotypic signatures and regulatory networks that distinguish the two programs. Aim 2. a and b) Combine experimental analyses with computational modeling to quantify the relative contributions from positive and negative regulation by Fus3 and Kss1 and the temporal control of transcription factor degradation on mediating the switch between alternative programs. Empirical measurements of transcription factor abundance and representative mRNAs in wild-type and mutant backgrounds that perturb regulation will be used to test the underlying hypotheses of the model. c) Time-lapse imaging under different pheromone induction regimes will be used to test whether a pheromone gradient reinforces feedback loops that regulate fluctuations and thereby reduce variability in pathway activity and fate determination. Our understanding of the pheromone induced MAPK pathway and the ease of genetic manipulations available with yeast allow discernment of how differences in the amplitude and timing of MAPK activation translate into different transcriptional patterns. Because of the conservation of MAPK pathways, the regulatory paradigms defined here will apply to different MAPK mediated signaling pathways in humans that are at the root of the pathogenesis of hormone dependent cancers, inflammatory diseases, and metabolic disorders. PUBLIC HEALTH RELEVANCE Mitogen activated protein kinase (MAPK) pathways control normal cellular development and function. Differences in the amplitude and timing of MAPK activation are known to affect whether cells divide and multiply or develop into a specialized cell types, such as liver, bone, or brain cells. This proposal exploits advantages of studies with the model genetic organism, S. cerevisiae, to define the molecular mechanisms that translate different patterns of MAPK activation into different developmental fates. The findings will give us a better understanding of how aberrant regulation of these pathways in humans leads to hormone dependent cancers, inflammatory diseases, and metabolic disorders such as Type II diabetes.

描述（由申请人提供）：协调转录程序以响应特定刺激的机制对于理解正常发育和体内平衡至关重要。信息素诱导的芽殖酵母向化学营养型或交配型的转变是剖析这种调节的分子基础的模型。单个丝裂原激活蛋白激酶 (MAPK) 级联介导这两种转变。该通路利用两个 MAPK（Fus3 和 Kss1），对 Ste12 和 Tec1 转录调节因子的活性进行负向和正向调节。 Ste12 对于基因表达的变化至关重要，而 Tec1 仅对化学营养命运重要。低信息素浓度诱导的趋化命运转变的遗传程序仍不清楚。 Fus3 和 Kss1 激活曲线在高信息素和低信息素下受到的影响不同。我们假设它们的激活和拮抗调节作用的剂量依赖性差异控制着 Ste12 和 Tec1 的活性和降解，从而为细胞的一种或另一种分化程序做好准备。我们提出了一种多学科方法来比较两种命运的调控网络和发育转换的分子基础： 目标 1. 使用微阵列技术定义趋化生长的全局表达程序，并将其与交配分化的表达程序进行比较。提出了生物信息学方法来描述区分这两个程序的生理和表型特征以及调控网络。目标 2. a 和 b) 将实验分析与计算模型相结合，量化 Fus3 和 Kss1 的正向和负向调节以及转录因子降解的时间控制对介导替代程序之间切换的相对贡献。对扰乱调节的野生型和突变体背景中转录因子丰度和代表性 mRNA 的经验测量将用于测试模型的基本假设。 c) 不同信息素诱导方案下的延时成像将用于测试信息素梯度是否增强调节波动的反馈回路，从而减少通路活动和命运决定的变异性。我们对信息素诱导的 MAPK 通路的了解以及酵母基因操作的简便性使我们能够辨别 MAPK 激活幅度和时间的差异如何转化为不同的转录模式。由于 MAPK 通路的保守性，此处定义的监管范式将适用于人类不同的 MAPK 介导的信号通路，这些通路是激素依赖性癌症、炎症性疾病和代谢紊乱发病机制的根源。公众健康相关性 丝裂原激活蛋白激酶 (MAPK) 途径控制正常的细胞发育和功能。众所周知，MAPK 激活的幅度和时间的差异会影响细胞是否分裂和增殖或发育成特殊的细胞类型，例如肝细胞、骨细胞或脑细胞。该提案利用了模型遗传生物酿酒酵母研究的优势，来定义将不同的 MAPK 激活模式转化为不同发育命运的分子机制。这些发现将使我们更好地了解人类这些途径的异常调节如何导致激素依赖性癌症、炎症性疾病和代谢紊乱（例如 II 型糖尿病）。