GROWTH RATE-DEPENDENT CONTROL OF GENE EXPRESSION

基因表达的生长速率依赖性控制

• 批准号: 3274529
• 负责人: Richard E Wolf
• 金额: $ 13.2万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE COUNTY
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-04-01 至 1987-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3274529
• 关键词: DNA; Escherichia coli; Salmonella typhimurium; bacterial virus; cell growth regulation; gene expression; genetic manipulation; genetic recombination; genetic strain; genetic transcription; microorganism metabolism; mutant; nucleic acid sequence; phosphogluconate dehydrogenase; structural genes

The gnd gene of Escherichia coli encodes 6-phosphogluconate dehydrogenase (6PGD), an enzyme of the hexose monophosphate shunt pathway of central intermediary metabolism. The levels of 6PGD are regulated by the cellular growth rate, increasing fourfold with increasing growth rate. Although this variation quantitatively resembles that observed for rRNA and r-proteins, results of our unpublished experiments on the effects of nutritional shifts and amino acid starvation on the rate of 6PGD synthesis demonstrated that the mechanism for growth rate control of 6PGD synthesis is distinct from that which regulates synthesis of rRNA and r-protein and is common to the regulation of many other proteins. The objective of the present proposal is to elucidate the mechanisms underlying the growth rate-dependent control of 6PGD synthesis. Several models for regulation of gnd are presented and used as a conceptual base for the design of experiments. Strains carrying gnd-lac operon and gene fusions will be prepared by the methods of Casadaban using our previously isolated gnd::Mucts mutants. The fusions will be used to determine whether growth rate-dependent control of 6PGD synthesis is transcriptional or post-transcriptional and for the isolation of mutants with mutations in gnd or unlinked to gnd which alter growth rate control. The DNA sequence of the gnd control region will be determined for wild type and mutant genes and for gnd of Salmonella typhimurium, which shows an altered growth rate response. S30 extracts will be prepared from wild type cells grown at different rates and from mutants, and used in DNA-dependent in vitro systems to identify and characterize the regulators of growth rate dependent control of 6PGD synthesis.

大肠杆菌的GND基因编码6-磷酸葡萄糖酸脱氢酶 （6pgd），中央己糖单磷酸根途径的酶 中介代谢。 6pgd的水平受细胞调节 增长率，随着增长率的增加而增加了四倍。 虽然这个 变异与rRNA和r蛋白观察到的变异相似， 我们未发表的实验的结果对营养转移的影响和 氨基酸饥饿的6pgd合成速率表明 6pgd合成的生长速率控制机制与 调节rRNA和R蛋白的合成，是对调节的共同 许多其他蛋白质。 本提案的目的是阐明基本机制 6pGD合成的生长速率依赖性控制。 几种模型 提出了GND的调节，并将其用作设计的概念基础 实验。 携带GND-LAC操纵子和基因融合的菌株将制备 通过使用我们先前隔离的gnd :: mucts突变体的Casadaban方法。 融合将用于确定是否依赖于增长率的控制 6pgd合成是转录或转录后的，用于隔离 具有GND突变或与GND无关的突变体的突变体的突变体改变了生长速率 控制。 将确定野生的GND控制区域的DNA序列 类型和突变基因以及鼠伤寒沙门氏菌的GND 增长率响应改变。 S30提取物将从野生型制备 以不同的速率和突变体生长的细胞，并用于DNA依赖性 识别和表征增长率调节因子的体外系统 6PGD合成的依赖控制。