The Regulation of a Neurosopora Glucose-repressible Gene

脉孢霉葡萄糖抑制基因的调控

• 批准号: 8904684
• 负责人: Stephen Free
• 金额: $ 26.82万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-15 至 1993-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8904684&HistoricalAwards=false
• 关键词: Regulation; Neurosopora; Glucose; repressible; Gene

For a variety of Filamentous fungi the level of extracellular glucose has been found to regulate the production of those extracellular hydrolases which mobilize alternative carbon and energy sources (proteases and carbohydrases). These glucose-repressible extracellular hydrolytic enzymes play an important role in fungal growth. Using Neurospora crassa as a model system we propose to study the molecular mechanisms responsible for the regulated expression of glucose-repressible genes in the filamentous fungi. We propose to identify DNA sequences which are required for the regulated expression of grg-l, a Neurospora glucose-repressible gene. The regulatory sequences will be defined by creating deletions and mutations in vitro and following the in vivo expression from these altered genes in Neurospora transformants. We propose to isolate and study a number of mutants affected in the ability to regulate the expression of glucose-repressible genes. Neurospora transformants containing chimeric genes will be used to generate the mutants. These mutants will be characterized by classical genetics techniques. A major effort will be made to study those proteins which specifically bind to the DNA sequences needed for the regulated expression of grg-l. We will assess the presence or absence of these DNA binding proteins in mutants affected in the ability to express glucose-repressible genes. By characterizing the grg-l regulatory region, the proteins which bind to this region, and the presence or absence of these proteins in mutants unable to regulate grg-l transcription, we hope to elucidate the molecular mechanisms responsible for the regulation of glucose-repressible genes in the filamentous fungi. Given a choice of nutrients many simple organisms (bacteria and fungi) preferentially utilize glucose when it is available. When growing in the simultaneous presence of glucose and other nutrients, these organisms make none of the enzymes necessary to digest the other nutrients until they have exhausted the supply of glucose. The enzymes for digestion of the other nutrients are said to be repressed by glucose. The mechanism of glucose repression is very well understood in some but not all species of bacteria, although some details are still obscure even in well characterized species. The mechanism is apparently much more complex in yeast than in bacteria, and hence is only partly understood. The mechanism in the mold Neurospora crassa is not understood at all, although there is reason to believe that it is as complex as in yeast, though differing in detail. This is a proposal to elucidate the mechanism of glucose repression in N. crassa. Apart from its own considerable intrinsic interest, this work may lead to information useful for the engineering of industrially useful strains of Neurospora.

对于多种丝状真菌， 已经发现葡萄糖可以调节那些 细胞外水解酶，其动员替代碳， 能量来源（蛋白酶和糖酶）。 这些 葡萄糖可抑制的胞外水解酶发挥作用， 在真菌生长中的重要作用。 利用粗糙脉孢菌作为 模型系统，我们建议研究的分子机制 负责葡萄糖抑制蛋白的调节表达 丝状真菌中的基因。 我们建议鉴定DNA 调控表达所需的序列， grg-1，链孢菌葡萄糖抑制基因。 监管 序列将通过创建缺失和突变来定义， 体外和体内表达后， 链孢霉转化体中的基因。 我们建议隔离和 研究了一些受影响的突变体， 葡萄糖抑制基因的表达。 脉孢 含有嵌合基因的转化体将用于产生 变种人 这些突变体将具有典型的 遗传学技术 将作出重大努力，研究 这些蛋白质特异性地与DNA序列结合， 调节GRG-1的表达。 我们将评估 或缺乏这些DNA结合蛋白在突变体中的影响， 表达葡萄糖抑制基因的能力。 通过 表征GRG-1调节区的蛋白质， 结合到这个区域，这些的存在或不存在， 突变体中的蛋白质不能调节GRG-1转录，我们 希望能阐明 丝状真菌中葡萄糖阻遏基因的调控。 如果有营养素的选择，许多简单的生物体（细菌和 真菌）优先利用葡萄糖。 当在葡萄糖和其他营养物质同时存在的情况下生长时， 营养素，这些生物体使没有必要的酶 消化其他的营养物质直到耗尽 葡萄糖。 消化其他营养物质的酶是 被葡萄糖抑制。 葡萄糖的作用机制 在一些但不是所有物种中， 细菌，虽然一些细节仍然模糊，即使在很好的 特征物种。 这个机制显然比 在酵母中比在细菌中更复杂，因此只是部分地 明白 在霉菌粗糙脉孢菌中， 尽管有理由相信， 和酵母一样复杂，只是细节不同 这是一 建议阐明葡萄糖阻遏的机制。 粗鲁。 除了自身的巨大利益， 工作可能会导致有用的信息工程 工业上有用的脉孢菌属菌株。