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、真菌和原生动物到植物和哺乳动物的所有细胞中。息肉由数百个磷酸残基组成的线性链组成，这些残基通过类ATP、高能、偏磷酸酐键连接在一起。人们已经提出了息肉的几种生物学功能，包括磷酸盐和能量的储存库，金属离子的螯合剂，抵御碱的缓冲器，以及DNA进入的通道。息肉似乎也在双组分信号转导中发挥作用，然而，人们对其生物学作用知之甚少。将在大肠杆菌中进行互补的分子遗传学和生理学实验，目的是更好地了解息肉在细胞生物学中的功能。实验旨在解决两个目标：第一是确定息肉激酶(PPK)-息肉磷酸酶(PPX)操纵子的遗传调节，第二是检查快速增加的息肉水平对体内基因调节的影响。

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.