GLOBAL GENE EXPRESSION IN E COLI--NITROGEN METABOLISM

我们将通过在微阵列上监测全局基因表达来研究大肠杆菌的调控途径。特别地，我们将研究氮的调控途径及其与通过常见中间物谷氨酸的渗透调控途径的联系。我们将创建大肠杆菌基因的微阵列，并开发大肠杆菌cdna的荧光标记方法。作为第一个练习，我们将使用微阵列来确定大肠杆菌中哪些基因受到氮调控C （NtrC）蛋白的调控控制。然后，我们将研究氮限制条件下所有基因的表达水平，以确定氮限制如何在初级谷氨酰胺限制的下游传播，从而减缓大肠杆菌的生长速度。最后，我们将探讨谷氨酸和K+在细胞渗透调节中的作用，以及谷氨酸在渗透调节和生物合成中的双重作用。我们开发的细菌基因表达监测系统将促进细菌的全球表达分析。

We will investigate regulatory pathways in E. coli by monitoring global gene expression on microarrays. In particular, we will study nitrogen regulatory pathways and their connection to osmoregulatory pathways through the common intermediate glutamate. We will create microarrays of E. coli genes and develop methods for fluorescent labeling of E. coli cDNAs. As a first exercise, we will use microarrays to determine which genes are under regulatory control of the nitrogen regulatory C (NtrC ) protein in E. coli. Then we will investigate expression levels of all genes under nitrogen limiting conditions to determine how nitrogen limitation propagates downstream of a primary glutamine limitation to slow the growth rate of E. coli. Finally, we will investigate the roles of glutamate and K+ in cellular osmoregulation and the dual role of glutamate in osmoregulation and biosynthesis. Our development of a system for gene expression monitoring in bacteria will facilitate global expression analyses in bacteria.