Second messenger c-di-GMP modulates exopolysaccharide Pea-dependent phenotypes via regulating eppA expression in Pseudomonas putida
Second messenger c-di-GMP modulates exopolysaccharide Pea-dependent phenotypes via regulating eppA expression in Pseudomonas putida
复制标题
第二信使 c-di-GMP 通过调节恶臭假单胞菌中 eppA 的表达来调节胞外多糖豌豆依赖性表型
DOI：
10.1128/aem.02270-21
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发表时间：
2022
影响因子：
4.4
通讯作者：
Qiaoyun Huang
中科院分区：
文献类型：
--
作者：
Yujie Xiao;Qingyuan Liang;Meina He;Nianqi Wu;Liang Nie;Wenli Chen;Qiaoyun Huang
豌豆胞外多糖（EPS）是恶臭假单胞菌的菌落形态、表膜形成和稳健的生物膜产生所必需的。第二信使环二鸟苷酸单磷酸（c-di-GMP）通过未知的机制诱导恶臭假单胞菌中的菌落形态。在此，我们发现c-di-GMP通过调节eppA（PP_5586）的表达来调节豌豆集落形态，eppA是一个独立转录的小基因，具有177个碱基对，并且该基因邻近豌豆簇的上游。表型观察表明eppA是豌豆依赖表型所必需的。eppA的缺失导致光滑的菌落形态和受损的生物膜，这类似于整个豌豆操纵子丢失的表型。c-di-GMP通过转录因子FleQ正向调节eppA的表达，eppA对c-di-GMP诱导的克隆形态是必不可少的。结构预测结果表明EppA具有两个跨膜区，Western blot结果表明EppA位于细胞膜上。转录组分析表明，EppA对恶臭假单胞菌的转录组没有显著影响。细菌双杂交（BTH）结果表明，EppA与豌豆簇蛋白及邻近操纵子之间没有直接的相互作用。总之，这些发现揭示了EppA对于Pea依赖性表型是必需的，并且c-di-GMP通过调节恶臭假单胞菌中的eppA表达来调节Pea依赖性表型。
Exopolysaccharides (EPSs) Pea is essential for wrinkly colony morphology, pellicle formation, and robust biofilm production in Pseudomonas putida. The second messenger cyclic diguanylate monophosphate (c-di-GMP) induces wrinkly colony morphology in P. putida through unknown mechanism(s). Herein, we found that c-di-GMP modulated wrinkly colony morphology via regulating expression of eppA (PP_5586), a small individually transcribed gene with 177 base pairs, and this gene was adjacent to the upstream of pea cluster. Phenotype observation revealed that eppA was essential for Pea-dependent phenotypes. The deletion of eppA led to smooth colony morphology and impaired biofilm, which was analogous to the phenotypes with the loss of the entire pea operon. EppA expression was positively regulated by c-di-GMP via the transcriptional effector FleQ, and eppA was essential for the c-di-GMP-induced wrinkly colony morphology. Structure prediction results implied that EppA had two transmembrane regions, and Western blot revealed that EppA was located on cell membrane. Transcriptomic analysis indicated that EppA had no significant effect on transcriptomic profile of P. putida. Bacterial two-hybrid (BTH) assay suggested that there was no direct interaction between EppA and the proteins in pea cluster and adjacent operons. Overall, these findings reveal that EppA is essential for Pea-dependent phenotypes, and that c-di-GMP modulates Pea-dependent phenotypes via regulating eppA expression in P. putida.