Studies on the signal transduction network in adaptive responses in microorganisms.

本研究的最终目的是了解细菌细胞中的信号转导网络。我们对铜绿假单胞菌磷饥饿适应反应系统中的信号转导进行了两年的研究，并对PI趋向性和磷酸盐调节进行了遗传分析。研究结果如下：1.碱性磷酸酶(AP)的结构性突变体APC1表现出结构性的PI趋向性。结果表明，存在一个共同的PI调节子和PI趋向性的负调控因子。1.染色体上的Phob突变体仍然显示出可诱导的PI趋性。2.克隆了一个27kb的DNA片段，该片段与APC1基因的突变互补。遗传分析表明，该负调控因子是PI特异的转运通道复合体。4.以趋化性缺失突变体为宿主菌株，通过枪击克隆获得了一个20kb的片段，遗传分析发现该片段上有两个趋化性基因Chey和chez。

The final goal of our research is to understand the signal transduction networks in a bacterial cell.We have focused on the signal transductions in the adaptation response system for phosphate starvation in Pseudomonas aeruginosa for two years and performedthe genetic analyzes of the Pi taxis and the phosphate regulon.The summary of research results is as follows :1.An constitutive alkaline phosphatase (AP) mutant, designated APC1, showed a constitutive phosphate (Pi) taxis.The result suggests the existence of a common negative regulator for the Pi regulon and the Pi taxis.1.A chromosomal phoB mutant still showed the inducible Pi taxis, indicating the Pi taxis is not regulated by the phoB gene unlike the Pi regulon.2.We cloned a 27-kb DNA fragment that complements the mutation of APC1.Genetic analyzes of the fragment revealed the negative regulator is the Pi specific transport channel complex.4.A 20-kb fragment was obtained by shot-gun cloning usibg a chemotaxis deficient mutant as a host strain.Two chemotaxis genes, cheY and cheZ were found on the fragment by genetic analyzes.