The SphS-SphR two component system is the exclusive sensor for the induction of gene expression in response to phosphate limitation in Synechocystis
The SphS-SphR two component system is the exclusive sensor for the induction of gene expression in response to phosphate limitation in Synechocystis
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DOI：
10.1074/jbc.m313358200
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发表时间：
2004-03-26
影响因子：
4.8
通讯作者：
Murata, N
中科院分区：
文献类型：
--
作者：
Suzuki, S;Ferjani, A;Murata, N
活生物体通过表达各种基因来响应磷酸盐限制，这些基因的产物在每个细胞内维持适当的磷酸盐浓度范围。我们以前确定了一个两个组件系统，其中包括组氨酸激酶SphS和它的同源反应调节SphR，调节磷酸盐限制条件下的蓝藻集胞藻属的碱性磷酸酶的phoA基因的表达。PCC 6803。在本研究中，我们使用DNA微阵列来研究SphS和SphR在调节磷酸盐限制引起的基因全基因组表达中的作用。在野生型细胞中，磷酸盐限制强烈诱导12个基因的表达，诱导因子大于7。这些基因包括在三个基因簇中，即编码磷酸盐转运蛋白的pst 1和pst 2簇; phoA基因和细胞外核酸酶的nucH基因。磷酸盐限制强烈抑制只有urtA基因的表达，诱导因子低于0.2。SphS或SphR的失活完全消除了12个基因的磷酸盐限制诱导表达和urtA基因的磷酸盐限制抑制表达。这些结果表明，SphS-SphR双组分系统集胞藻PCC 6803是占主导地位的感觉系统，控制基因表达响应磷酸盐限制。
Living organisms respond to phosphate limitation by expressing various genes whose products maintain an appropriate range of phosphate concentrations within each cell. We identified previously a two component system, which consists of histidine kinase SphS and its cognate response regulator SphR, which regulates the expression of the phoA gene for alkaline phosphatase under phosphate-limiting conditions in the cyanobacterium Synechocystis sp. PCC 6803. In the present study, we used DNA microarrays to investigate the role of SphS and SphR in the regulation of the genome-wide expression of genes in response to phosphate limitation. In wild-type cells, phosphate limitation strongly induced the expression of 12 genes with induction factors greater than 7. These genes were included in three clusters of genes, namely, the pst1 and pst2 clusters that encode phosphate transporters; the phoA gene and the nucH gene for the extracellular nuclease. Phosphate limitation strongly repressed the expression of only the urtA gene with induction factors below 0.2. Inactivation of either of SphS or SphR completely eliminated the phosphate limitation-inducible expression of the 12 genes and the phosphate limitation-repressible expression of the urtA gene. These results suggest that the SphS-SphR two component system in Synechocystis sp. PCC 6803 is the dominant sensory system that controls gene expression in response to phosphate limitation.