Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Sevilla, Spain.
Plant Signal Behav. 2012 Dec;7(12):1712-4. doi: 10.4161/psb.22323. Epub 2012 Oct 16.
Copper is essential for all living organisms but is toxic when present in excess. Therefore organisms have developed homeostatic mechanism to tightly regulate its cellular concentration. In a recent study we have shown that CopRS two-component system is essential for copper resistance in the cyanobacterium Synechocystis sp PCC 6803. This two-component regulates expression of a heavy-metal RND type copper efflux system (encoded by copBAC) as well as its own expression (in the copMRS operon) in response to an excess of copper in the media. We have also observed that both operons are induced under condition that reduces the photosynthetic electron flow and this induction depends on the presence of the copper-protein, plastocyanin. These findings, together with CopS localization to the thylakoid membrane and its periplasmic domain being able to bind copper directly, suggest that CopS could be involved in copper detection in both the periplasm and the thylakoid lumen.
铜对于所有生物都是必需的，但过量存在时会有毒性。因此，生物已经发展出了体内平衡机制来严格调节其细胞内浓度。在最近的一项研究中，我们已经表明，CopRS 双组分系统对于蓝藻集胞藻 PCC 6803 的铜抗性是必不可少的。该双组分系统调节重金属 RND 型铜外排系统（由 copBAC 编码）的表达以及其自身的表达（在 copMRS 操纵子中），以响应培养基中过量的铜。我们还观察到，这两个操纵子在减少光合电子流的条件下被诱导，这种诱导依赖于铜蛋白蓝铜蛋白的存在。这些发现，以及 CopS 定位于类囊体膜及其周质域能够直接结合铜，表明 CopS 可能参与了周质和类囊体腔中铜的检测。
