Photosensing and quorum sensing are integrated to control Pseudomonas aeruginosa collective behaviors.

TitlePhotosensing and quorum sensing are integrated to control Pseudomonas aeruginosa collective behaviors.
Publication TypeJournal Article
Year of Publication2019
AuthorsMukherjee, S, Jemielita, M, Stergioula, V, Tikhonov, M, Bassler, BL
JournalPLoS Biol
Volume17
Issue12
Paginatione3000579
Date Published2019 12
ISSN1545-7885
KeywordsBacterial Proteins, Biofilms, DNA-Binding Proteins, Gene Expression Regulation, Bacterial, Phosphorylation, Phosphotransferases, Photoreceptors, Microbial, Pseudomonas aeruginosa, Quorum Sensing, Transcription Factors, Virulence
Abstract

Bacteria convert changes in sensory inputs into alterations in gene expression, behavior, and lifestyles. A common lifestyle choice that bacteria make is whether to exhibit individual behavior and exist in the free-living planktonic state or to engage in collective behavior and form sessile communities called biofilms. Transitions between individual and collective behaviors are controlled by the chemical cell-to-cell communication process called quorum sensing. Here, we show that quorum sensing represses Pseudomonas aeruginosa biofilm formation and virulence by activating expression of genes encoding the KinB-AlgB two-component system (TCS). Phospho-AlgB represses biofilm and virulence genes, while KinB dephosphorylates and thereby inactivates AlgB. We discover that the photoreceptor BphP is the kinase that, in response to light, phosphorylates and activates AlgB. Indeed, exposing P. aeruginosa to light represses biofilm formation and virulence gene expression. To our knowledge, P. aeruginosa was not previously known to detect and respond to light. The KinB-AlgB-BphP module is present in all pseudomonads, and we demonstrate that AlgB is the partner response regulator for BphP in diverse bacterial phyla. We propose that in the KinB-AlgB-BphP system, AlgB functions as the node at which varied sensory information is integrated. This network architecture provides a mechanism enabling bacteria to integrate at least two different sensory inputs, quorum sensing (via RhlR-driven activation of algB) and light (via BphP-AlgB), into the control of collective behaviors. This study sets the stage for light-mediated control of P. aeruginosa infectivity.

DOI10.1371/journal.pbio.3000579
Alternate JournalPLoS Biol.
PubMed ID31830037
PubMed Central IDPMC6932827
Grant List / HHMI / Howard Hughes Medical Institute / United States
R37 GM065859 / GM / NIGMS NIH HHS / United States
K99 GM129424 / GM / NIGMS NIH HHS / United States