Functional characterization of a csoR-cueA divergon in Bradyrhizobium liaoningense CCNWSX0360, involved in copper, zinc and cadmium cotolerance.
Functional characterization of a csoR-cueA divergon in Bradyrhizobium liaoningense CCNWSX0360, involved in copper, zinc and cadmium cotolerance.
复制标题
辽宁慢生根瘤菌 CCNWSX0360 中 csoR-cueA divergon 的功能表征，涉及铜、锌和镉耐受性
DOI：
10.1038/srep35155
复制
发表时间：
2016-10-11
影响因子：
4.6
通讯作者：
Wei G
中科院分区：
文献类型：
--
作者：
Liang J;Zhang M;Lu M;Li Z;Shen X;Chou M;Wei G
利用Tn5对共生固氮缓生根瘤菌辽宁根瘤菌CCNWSX0360 （Bln0360）进行随机诱变，鉴定出5个铜抗性相关基因。它们在功能上分为三组：跨膜转运（cueA和tolC）；氧化(国王);保护膜屏障（lptE和ctpA）。cueA基因与上游的Cu敏感操纵子抑制因子csoR （Cu-sensitive operon repressor）共同构成了csoR-cueA分支，在Cu稳态中起着至关重要的作用。cueA的缺失降低了细胞对铜的耐受性，而该突变体的补充恢复了与野生型相当的铜抗性。转录和融合表达分析表明，一价Cu+和二价Zn2+/Cd2+均可上调CsoR - cuea辐散，而转录抑制因子CsoR通过双向启动子对其进行负调控。csoR的缺失使细胞对Cu、Zn和Cd具有超强的抗性。尽管预计会编码Cu转运p型atp酶（CueA），但CueA也具有对锌和镉的抗性；Cu/Zn/Cd耐受性需要两个假定的CueA N-MBDs （n端金属结合域）。此外，在富铜条件下，辽宁白杨的结瘤竞争力还需要cueA。综上所述，这些结果证明了csoR-cueA分支作为辽宁白刺多金属抗性机制的一个组成部分的关键作用。
Random mutagenesis in a symbiotic nitrogen-fixing Bradyrhizobium liaoningense CCNWSX0360 (Bln0360) using Tn5 identified five copper (Cu) resistance-related genes. They were functionally sorted into three groups: transmembrane transport (cueA and tolC); oxidation (copA); and protection of the membrane barrier (lptE and ctpA). The gene cueA, together with the upstream csoR (Cu-sensitive operon repressor), constituted a csoR-cueA divergon which plays a crucial role in Cu homeostasis. Deletion of cueA decreased the Cu tolerance of cells, and complementation of this mutant restored comparable Cu resistance to that of the wild-type. Transcriptional and fusion expression analysis demonstrated that csoR-cueA divergon was up-regulated by both the monovalent Cu+ and divalent Zn2+/Cd2+, and negatively regulated by transcriptional repressor CsoR, via a bidirectional promoter. Deletion of csoR renders the cell hyper-resistant to Cu, Zn and Cd. Although predicted to encode a Cu transporting P-type ATPase (CueA), cueA also conferred resistance to zinc and cadmium; two putative N-MBDs (N-terminal metal binding domains) of CueA were required for the Cu/Zn/Cd tolerance. Moreover, cueA is needed for nodulation competitiveness of B. liaoningense in Cu rich conditions. Together, the results demonstrated a crucial role for the csoR-cueA divergon as a component of the multiple-metal resistance machinery in B. liaoningense.
登录
查看更多内容
影响因子：
4.1
作者：
Kaneko, T;Nakamura, Y;Tabata, S
通讯作者：
Tabata, S
影响因子：
3
作者：
Andreini, Claudia;Bertini, Ivano;Thornton, Janet M.
通讯作者：
Thornton, Janet M.
影响因子：
4.8
作者：
Fan, B;Rosen, BP
通讯作者：
Rosen, BP
影响因子：
3.2
作者：
Grass, G;Fan, B;Rensing, C
通讯作者：
Rensing, C
影响因子：
4.8
作者：
Chang, Feng-Ming James;Coyne, H. Jerome;Giedroc, David P.
通讯作者：
Giedroc, David P.