The phosphodiesterase DibA interacts with the c‐di‐GMP receptor LapD and specifically regulates biofilm in Pseudomonas putida

• Published in: Molecular microbiology Vol. 121; no. 1; pp. 1 - 17
• Main Authors: Nie, Hailing, Nie, Liang, Xiao, Yujie, Song, Miaomiao, Zhou, Tiantian, He, Jinzhi, Chen, Wenli, Huang, Qiaoyun
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-01-2024
• Subjects: adhesin LapA; Bacterial Proteins - metabolism; biofilm; Biofilms; Carrier Proteins - metabolism; Cell membranes; Cell surface; Cyclic GMP - metabolism; c‐di‐GMP receptor LapD; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Gene Expression Regulation, Bacterial; Genes; Genomes; Phosphodiesterase; phosphodiesterase DibA; Phosphoric Diester Hydrolases - genetics; Phosphoric Diester Hydrolases - metabolism; protein–protein interaction; Pseudomonas putida; Pseudomonas putida - genetics; Pseudomonas putida - metabolism; Receptors; adhesin LapA; protein-protein interaction; c-di-GMP receptor LapD; Pseudomonas putida; biofilm; phosphodiesterase DibA
• ISSN: 0950-382X; 1365-2958
• DOI: 10.1111/mmi.15189

The ubiquitous bacterial second messenger c‐di‐GMP is synthesized by diguanylate cyclase and degraded by c‐di‐GMP‐specific phosphodiesterase. The genome of Pseudomonas putida contains dozens of genes encoding diguanylate cyclase/phosphodiesterase, but the phenotypical–genotypical correlation and functional mechanism of these genes are largely unknown. Herein, we characterize the function and mechanism of a P. putida phosphodiesterase named DibA. DibA consists of a PAS domain, a GGDEF domain, and an EAL domain. The EAL domain is active and confers DibA phosphodiesterase activity. The GGDEF domain is inactive, but it promotes the phosphodiesterase activity of the EAL domain via binding GTP. Regarding phenotypic regulation, DibA modulates the cell surface adhesin LapA level in a c‐di‐GMP receptor LapD‐dependent manner, thereby inhibiting biofilm formation. Moreover, DibA interacts and colocalizes with LapD in the cell membrane, and the interaction between DibA and LapD promotes the PDE activity of DibA. Besides, except for interacting with DibA and LapD itself, LapD is found to interact with 11 different potential diguanylate cyclases/phosphodiesterases in P. putida, including the conserved phosphodiesterase BifA. Overall, our findings demonstrate the functional mechanism by which DibA regulates biofilm formation and expand the understanding of the LapD‐mediated c‐di‐GMP signaling network in P. putida.
The phosphodiesterase DibA interacts with the c‐di‐GMP receptor LapD to regulate the content of LapA on the cell surface, thereby inhibiting the biofilm formation of Psudomonas putida. The results of this study deepen our understanding of the specific regulation of biofilm by c‐di‐GMP signal transduction.