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

Sampriti Mukherjee, Matthew Jemielita, Vasiliki Stergioula, Mikhail Tikhonov, Bonnie L. Bassler

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


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.

Original languageEnglish (US)
Article numbere3000579
JournalPLoS biology
Issue number12
StatePublished - 2019

All Science Journal Classification (ASJC) codes

  • General Agricultural and Biological Sciences
  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology
  • General Neuroscience


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