Inverse transcriptional activities during complementary chromatic adaptation are controlled by the response regulator RcaC binding to red and green light-responsive promoters
Inverse transcriptional activities during complementary chromatic adaptation are controlled by the response regulator RcaC binding to red and green light-responsive promoters
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DOI：
10.1111/j.1365-2958.2008.06151.x
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发表时间：
2008-04-01
影响因子：
3.6
通讯作者：
Kehoe, David M.
中科院分区：
文献类型：
--
作者：
Li, Lina;Alvey, Richard M.;Kehoe, David M.
互补色适应（CCA）为蓝细菌提供了在红色和蓝绿色表型之间转换的能力，这些表型针对不同波长的光的吸收进行了优化。由绿色与红光的比例控制，该过程由两组操纵子的差异表达引起，其中许多操纵子编码参与光合捕光天线生物发生的蛋白质。在淡水物种Fremyella diplosiphon中，这两类的反向调节是复杂的，并通过不同的机制发生。它还涉及一个双组分途径，包括光敏色素类光感受器和反应调节剂RcaC。在这里，我们揭示了该系统控制CCA的机制，通过证明RcaC结合到L盒内的两类光调节操纵子的启动子。我们提供的功能证据表明，这些操纵子的互补调节发生RcaC的同时激活和抑制转录在红光。我们确定rcaC和L盒的基因组中的海洋蓝藻能够CCA，这表明广泛使用的控制系统。这些结果提供了重要的见解，长期以来的谜CCA监管和完成的第一个描述的一个完整的双组分系统控制的光敏色素类感光体。
Complementary chromatic adaptation (CCA) provides cyanobacteria with the ability to shift between red and blue-green phenotypes that are optimized for absorption of different wavelengths of light. Controlled by the ratio of green to red light, this process results from differential expression of two groups of operons, many of which encode proteins involved in photosynthetic light harvesting antennae biogenesis. In the freshwater species Fremyella diplosiphon, the inverse regulation of these two classes is complex and occurs through different mechanisms. It also involves a two-component pathway that includes a phytochrome-class photoreceptor and the response regulator RcaC. Here we uncover the mechanism through which this system controls CCA by demonstrating that RcaC binds to the L Box within promoters of both classes of light-regulated operons. We provide functional evidence that complementary regulation of these operons occurs by RcaC's simultaneous activation and repression of transcription in red light. We identify rcaC and L Boxes in the genome of a marine cyanobacterium capable of CCA, suggesting widespread use of this control system. These results provide important insights into the long-standing enigma of CCA regulation and complete the first description of an entire two-component system controlled by a phytochrome-class photoreceptor.