Differential Regulation of Six Heavy Metal Efflux Systems in the Response of Myxococcus xanthus to Copper
Differential Regulation of Six Heavy Metal Efflux Systems in the Response of Myxococcus xanthus to Copper
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DOI：
10.1128/aem.00753-10
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发表时间：
2010-09-01
影响因子：
4.4
通讯作者：
Munoz-Dorado, Jose
中科院分区：
文献类型：
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作者：
Moraleda-Munoz, Aurelio;Perez, Juana;Munoz-Dorado, Jose
黄色粘球菌在生长和发育过程中必须科普环境的变化。在这些因素中，铜的浓度是至关重要的，因为这种金属的基本毒性作用迫使细胞保持紧密的稳态。分枝xanthus对铜的反应比其他细菌更为复杂，这反映在生长和发育细胞对铜的敏感性不同。在本研究中，对M。Xanthus基因组已被检查。这些泵中的三个表现出Cus系统的跨膜结构域4中的特征序列（Cus1、Cus2和Cus3），而其他三个表现出Czc系统的基序（Czc1、Czc2和Czc3）。Cus2和Cus3系统是由铜和单价金属诱导的，作为主要的铜外排泵，而Cus1系统涉及Zn 2+稳态。Czc系统也受到二价金属但不受铜（Czc1）、铜和二价金属（Czc2）或饥饿（Czc3）的差异调节。这六个外排系统的差动调节保证了M.在铜和其他金属浓度波动的环境中，黄藻的生命周期。
Myxococcus xanthus has to cope with changes in its environment during growth and development. Among these factors, the concentration of copper is crucial due to the essential toxic effect of this metal, which forces the cells to maintain a tight homeostasis. The M. xanthus copper response is more complex than that in other bacteria, which is reflected by the different copper sensitivities of growing and developing cells. In the present study, the participation in copper homeostasis of six heavy metal efflux systems encoded in the M. xanthus genome has been examined. Three of these pumps exhibit the signature sequences in transmembrane domain 4 of the Cus systems (Cus1, Cus2, and Cus3), while the other three exhibit the motifs of the Czc systems (Czc1, Czc2, and Czc3). The Cus2 and Cus3 systems are inducible by copper and monovalent metals, functioning as the main copper efflux pumps, while the Cus1 system is implicated in Zn2+ homeostasis. The Czc systems are also differentially regulated either by divalent metals but not by copper (Czc1), by copper and divalent metals (Czc2), or by starvation (Czc3). The differential regulation of these six efflux systems ensures the proper completion of the M. xanthus life cycle in an environment with fluctuating concentrations of copper and other metals.