Cross Regulation and Central Metabolism in Bacteria

聚磷酸盐（polyP）是一种普遍存在的聚合物，存在于从古细菌、真细菌、真菌、原生动物到植物和哺乳动物的所有细胞中。PolyP由数百个磷酸残基的线性链组成，这些磷酸残基由类似atp的高能磷酸酐（偏磷酸）键连接。人们认为息肉具有多种生物学功能，包括储存磷酸盐和能量、螯合金属离子、缓冲碱和DNA进入通道。息肉也似乎在双组分信号转导中起作用，然而，其生物学作用尚不清楚。为了更好地了解polyP在细胞生物学中的功能，我们将在大肠杆菌中进行互补的分子遗传学和生理学实验。实验旨在解决两个目标：第一个目标是确定polyP激酶(ppk)-polyP磷酸酶（ppx）操纵子的遗传调控，第二个目标是检查体内快速增加的polyP水平对基因调控的影响。

Polyphosphate (polyP) is a ubiquitous polymer found in all cells from archaea, eubacteria, fungi, and protozoa to plants and mammals. PolyP is comprised of a linear chain of hundreds of phosphate residues linked by ATP-like, high-energy, phosphoanhydride metaphosphate) bonds. Several biological functions have been suggested for polyP, including a reservoir for phosphate and energy, a chelator of metal ions, a buffer against alkali, and a channel for DNA entry. PolyP also appears to have a role in two-component signal transduction, yet, its biological role is poorly understood. Complementary molecular genetic and physiology experiments will be carried out in the bacterium Escherichia coli with the goal of better understanding the function of polyP in cell biology. Experiments are being directed towards addressing two aims: the first is to define the genetic regulation of the polyP kinase (ppk)-polyP phosphatase (ppx) operon, and the second is to examine the consequences of rapidly increasing polyP levels on gene regulation in vivo.