title: Expression of the diguanylate cyclase GcbA is regulated by FleQ in response to cyclic di-GMP in Pseudomonas putida KT2440.
abstract: Cyclic di-GMP (c-di-GMP), a ubiquitous bacterial second messenger that regulates diverse cellular processes, is synthesized by diguanylate cyclase (DGC) and degraded by phosphodiesterase (PDE). GcbA is a well conserved DGC among Pseudomonas species, and has been reported to influence biofilm formation and flagellar motility in Pseudomonas fluorescens and Pseudomonas aeruginosa. Here we confirm the function of GcbA in Pseudomonas putida and reveal that expression of GcbA is regulated by FleQ in response to c-di-GMP. GcbA deletion impaired initial biofilm formation and enhanced swimming motility, but showed no influence on biofilm maturation in Pseudomonas putida. Deletion of the c-di-GMP effector FleQ led to a significant decrease in transcription of gcbA. Moreover, reducing c-di-GMP levels promoted gcbA transcription in a FleQ dependent way, while enhancing c-di-GMP levels abolished the promotion. In in vitro experiments we found that FleQ bound to gcbA promoter DNA and the binding was inhibited by c-di-GMP. Besides, FleN, an anti-activator of FleQ, and the sigma factor RpoN also participated in transcription of gcbA. Our finding expands the complexity of FleQ-dependent regulation and reveals a self-regulation function of c-di-GMP by regulating GcbA expression via FleQ.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Hailing
authors.initials: H
authors.lastname: Nie
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Huizhong
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.|Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Huang
mesh_terms: D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D029968:Escherichia coli Proteins / Q000096:biosynthesis*; D017353:Gene Deletion; D005786:Gene Expression Regulation; D019761:Phosphorus-Oxygen Lyases / Q000096:biosynthesis*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D015534:Trans-Activators; C062025:bis(3',5')-cyclic diguanylic acid; D019761:Phosphorus-Oxygen Lyases; C060720:diguanylate cyclase; D006152:Cyclic GMP