Cross talk and Metabolism in Escherichia coli

大肠杆菌的串扰和代谢

• 批准号: 9108005
• 负责人: Barry Wanner
• 金额: $ 27万
• 依托单位: Purdue Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-15 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9108005&HistoricalAwards=false
• 关键词: Cross; talk; Metabolism; Escherichia; coli

This project is to study the genetic and molecular basis of regulatory interactions termed cross talk between the phosphate (PHO) regulon and genes in the creABCD, formerly called phoM, operon and to define the biological role of the creABCD operon in Escherichia coli. The project focuses entirely on regulatory interactions involving the creABCD operon. The PHO regulon encodes genes for the acquisition of environmental phosphorus (P) and is induced when the external (ext) inorganic phosphate (Pi) level is growth limiting. The creABCD operon, whose expression is unaffected by Pi(ext), seems to respond to the level of an internal (int) organophosphate formed in central metabolism, which may be formed in substrate-level phosphorylation (in glycolysis or the TCA cycle) at a step where Pi(int) is incorporated into organophosphate. Regulatory interactions are expected between genes in a metabolic pathway; Pi(ext) to Pi(int) to organophosphate (int) in which Pi(ext) regulates the PHO regulon and organophosphate(int) may regulate both the PHO regulon and the creABCD operon. Such cross talk may be an example of an underlying control mechanisms essential for general (global) control of cell metabolism and growth; this is especially apparent in the control of gene expression in bacteria, but may quite possibly play the same role in eucaryotic cells too.

本项目旨在研究磷酸盐（PHO）调控子与creABCD（以前称为phoM）操纵子基因之间的互扰调控相互作用的遗传和分子基础，并确定creABCD操纵子在大肠杆菌中的生物学作用。该项目完全侧重于涉及creABCD操纵子的调控相互作用。PHO调控子编码获取环境磷(P)的基因，并在外部无机磷酸盐（Pi）水平限制生长时被诱导。creABCD操纵子的表达不受Pi（外）的影响，似乎对中心代谢中形成的内部（int）有机磷的水平有反应，这可能是在底物水平的磷酸化（在糖酵解或TCA循环中）中Pi（int）被纳入有机磷的步骤形成的。代谢途径中基因之间的调节相互作用是预期的；Pi（ext）到Pi（int）到有机磷酸酯（int），其中Pi（ext）调控PHO调控子，而有机磷酸酯（int）可能同时调控PHO调控子和creABCD操纵子。这种串扰可能是细胞代谢和生长的一般（整体）控制所必需的潜在控制机制的一个例子；这在细菌基因表达的控制中尤其明显，但很可能在真核细胞中也起着同样的作用。