Dissecting the wiring of yeast's glucose sensing circuit

描述(申请人提供)：几乎所有的生命都依赖于来自葡萄糖的能量。需要检测和响应环境中这种普遍存在的单糖的存在，导致了有效吸收和利用它的复杂机制的演变。酿酒酵母为细胞如何响应和代谢这种简单的糖提供了一个独特的例子。这种酵母即使在氧气存在的情况下也喜欢发酵葡萄糖，这是它与某些肿瘤细胞的共同特征，尽管氧化会产生更多的能量。这种偏爱并不是因为没有用于氧化的酶，而是因为它们受到葡萄糖的严格调节。这是葡萄糖诱导和抑制基因表达的两条主要途径的结果，这两条途径高度相互关联，每一条途径都影响另一条效应物的表达或活性。这些跨途径的相互作用可能赋予这一调节电路反馈和前馈控制，使系统能够对不断变化的血糖水平做出快速和动态的反应。通过扰乱和重新连接这些控制电路，它们对整个系统的贡献将通过监测基因调控、代谢物生产和竞争性生长实验中完整网络的选择优势来衡量。了解这两条途径是如何整合的，将使我们对酵母最重要的调控电路之一的知识更上一层楼。

DESCRIPTION (provided by applicant): Nearly all life depends on energy derived from glucose. The necessity to detect and respond to the presence of this ubiquitous monosaccharide in the environment has resulted in the evolution of sophisticated mechanisms for its efficient uptake and utilization. The yeast S. cerevisiae provides a unique example of how cells respond to and metabolize this simple sugar. This yeast prefers to ferment glucose even in the presence of oxygen, a trait that it shares with certain tumor cells, even though oxidation would yield far more energy. This preference is not due to the absence of the enzymes used in oxidation, but to their stringent regulation by glucose. This is the result of two major pathways for glucose-mediated induction and repression of gene expression that are highly interconnected, with each pathway influencing the expression or activity of effectors in the other. These cross-pathway interactions may endow this regulatory circuit with both feedback and feedforward controls that may give the system the ability to respond rapidly and dynamically to changing levels of glucose. By disrupting and rewiring these control circuits their contributions to the overall system will be measured by monitoring gene regulation, metabolite production, and the selective advantage of an intact network in competitive growth experiments. Understanding how these two pathways are integrated will add another level to our knowledge of one of yeast's most important regulatory circuits.