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Expression of the diguanylate cyclase GcbA is regulated by FleQ in response to cyclic di‐GMP in Pseudomonas putida KT2440
Author(s) -
Xiao Yujie,
Nie Hailing,
Liu Huizhong,
Chen Wenli,
Huang Qiaoyun
Publication year - 2016
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12478
Subject(s) - rpon , pseudomonas putida , biology , pseudomonas fluorescens , sigma factor , biofilm , microbiology and biotechnology , transcription (linguistics) , motility , phosphodiesterase , promoter , biochemistry , gene expression , genetics , bacteria , gene , enzyme , linguistics , philosophy
Summary 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.