Open AccessIdentification of c-di-GMP/FleQ-Regulated New Target Genes, Including cyaA , Encoding Adenylate Cyclase, in Pseudomonas putida
Author(s) -
Yujie Xiao,
Haozhe Chen,
Liang Nie,
Meina He,
Qi Peng,
Wenjing Zhu,
Hailing Nie,
Wenli Chen,
Qiaoyun Huang
Publication year - 2021
Publication title -
msystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.931
H-Index - 39
ISSN - 2379-5077
DOI - 10.1128/msystems.00295-21
Subject(s) - gene , adenylate kinase , pseudomonas putida , identification (biology) , biology , genetics , biochemistry , enzyme , botany
The bacterial second messenger cyclic diguanylate (c-di-GMP) modulates plankton-to-biofilm lifestyle transition of Pseudomonas species through its transcriptional regulatory effector FleQ. FleQ regulates transcription of biofilm- and flagellum-related genes in response to c-di-GMP. Through transcriptomic analysis and FleQ-DNA binding assay, this study identified five new target genes of c-di-GMP/FleQ in P. putida , including PP_0681 , PP_0788 , PP_4519 ( lapE ), PP_5222 ( cyaA ), and PP_5586 Except lapE encoding an outer membrane pore protein and cyaA encoding an adenylate cyclase, the functions of the other three genes encoding hypothetical proteins remain unknown. FleQ and c-di-GMP coordinately inhibit transcription of PP_0788 and cyaA and promote transcription of PP_0681 , lapE , and PP_5586 Both in vitro and in vivo assays show that FleQ binds directly to promoters of the five genes. Further analyses confirm that LapE plays a central role of in the secretion of adhesin LapA and that c-di-GMP/FleQ increases lapE transcription, thereby promoting adhesin secretion and biofilm formation. The adenylate cyclase CyaA is responsible for synthesis of another second messenger, cyclic AMP (cAMP). FleQ and c-di-GMP coordinate to decrease the content of cAMP, suggesting that c-di-GMP and FleQ coregulate cAMP by modulating cyaA expression. Overall, this study adds five new members to the c-di-GMP/FleQ-regulated gene family and reveals the role of c-di-GMP/FleQ in LapA secretion and cAMP synthesis regulation in P. putida IMPORTANCE c-di-GMP/FleQ promotes the plankton-to-biofilm lifestyle transition at the transcriptional level via FleQ in Pseudomonas species. Identification of new target genes directly regulated by c-di-GMP/FleQ helps to broaden the knowledge of c-di-GMP/FleQ-mediated transcriptional regulation. Regulation of lapE by c-di-GMP/FleQ guarantees highly efficient LapA secretion and biofilm formation. The mechanism of negative correlation between c-di-GMP and cAMP in both P. putida and P. aeruginosa remains unknown. Our result concerning transcriptional inhibition of cyaA by c-di-GMP/FleQ reveals the mechanism underlying the decrease of cAMP content by c-di-GMP in P. putida .