The PolS-PolR Two-Component System Regulates Genes Involved in Poly-P Metabolism and Phosphate Transport in Microlunatus phosphovorus
The PolS-PolR Two-Component System Regulates Genes Involved in Poly-P Metabolism and Phosphate Transport in Microlunatus phosphovorus
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DOI：
10.3389/fmicb.2019.02127
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发表时间：
2019-09
影响因子：
5.2
通讯作者：
Chuanqing Zhong;Peipei Zhang;Cheng Liu;Meng Liu;Wen-bing Chen;Jiafang Fu;Xiaoyu Qi;Guangxiang Cao-Guang
中科院分区：
文献类型：
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作者：
Chuanqing Zhong;Peipei Zhang;Cheng Liu;Meng Liu;Wen-bing Chen;Jiafang Fu;Xiaoyu Qi;Guangxiang Cao-Guang
Microlunatus phosphovorus NM-1是一株聚磷菌，在好氧条件下能积累聚磷，在厌氧条件下能降解聚磷。在本研究中，在NM-1中鉴定了双组分系统（TCS）PolS-PolR，并发现响应调节剂PolR直接与磷酸盐转运（MLP_RS00235、MLP_RS23035和MLP_RS24590）、聚磷催化剂（MLP_RS12905）和聚磷合成（MLP_RS23025）相关基因的启动子结合。RT-qPCR试验显示，ppgk（MLP_RS12905）、ppk（MLP_RS23025）、pstS（MLP_RS23035）和pit（MLP_RS24590）在好氧-厌氧转换期间下调。序列GTTCACnnnnnGTTCaC通过MEME分析和DNA酶I足迹法鉴定为PolR的识别序列。EMSA和ChIP-qPCR试验表明，PolR与pit（MLP_RS00235）、ppgk（MLP_RS12905）、ppk（MLP_RS23025）、pstS（MLP_RS23035）和pit（MLP_RS24590）的启动子结合，ChIP-qPCR进一步表明，体内厌氧条件下PolR的结合亲和力低于需氧条件下。这些结果表明，PolS-PolR TCS在M。磷酸菌可能参与调节多聚磷代谢以响应环境中溶解氧的水平，我们的结果为了解磷积累和释放机制的新方法提供了见解。
Microlunatus phosphovorus NM-1 is a polyphosphate (poly-P)-accumulating bacterium that accumulates poly-P under aerobic conditions and degrades poly-P under anaerobic conditions. In this study, the two-component system (TCS) PolS-PolR was identified in NM-1, and the response regulator PolR was found to directly bind to the promoters of genes related to phosphate transport (MLP_RS00235, MLP_RS23035, and MLP_RS24590); poly-P catabolism (MLP_RS12905) and poly-P synthesis (MLP_RS23025). RT-qPCR assays showed that ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035), and pit (MLP_RS24590) were down-regulated during the aerobic-anaerobic shift. The sequence GTTCACnnnnnGTTCaC was identified as a recognition sequence for PolR by MEME analysis and DNase I footprinting. EMSAs and ChIP-qPCR assays indicated that PolR binds to the promoters of pit (MLP_RS00235), ppgk (MLP_RS12905), ppk (MLP_RS23025), pstS (MLP_RS23035) and pit (MLP_RS24590), and ChIP-qPCR further suggested that the binding affinity of PolR was lower under anaerobic conditions than under aerobic conditions in vivo. These findings indicate that the PolS-PolR TCS in M. phosphovorus may be involved in the regulation of poly-P metabolism in response to levels of dissolved oxygen in the environment, and our results provide insights into new approaches for understanding the mechanisms of phosphorus accumulation and release.