Type IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa.

TitleType IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa.
Publication TypeJournal Article
Year of Publication2015
AuthorsPersat, A, Inclan, YF, Engel, JN, Stone, HA, Gitai, Z
JournalProc Natl Acad Sci U S A
Volume112
Issue24
Pagination7563-8
Date Published2015 Jun 16
ISSN1091-6490
KeywordsBacterial Adhesion, Biophysical Phenomena, Cyclic AMP, Fimbriae Proteins, Fimbriae, Bacterial, Genes, Bacterial, Mechanotransduction, Cellular, Models, Biological, Molecular Motor Proteins, Mutation, Operon, Pseudomonas aeruginosa, Virulence Factors
Abstract

<p>Bacteria have evolved a wide range of sensing systems to appropriately respond to environmental signals. Here we demonstrate that the opportunistic pathogen Pseudomonas aeruginosa detects contact with surfaces on short timescales using the mechanical activity of its type IV pili, a major surface adhesin. This signal transduction mechanism requires attachment of type IV pili to a solid surface, followed by pilus retraction and signal transduction through the Chp chemosensory system, a chemotaxis-like sensory system that regulates cAMP production and transcription of hundreds of genes, including key virulence factors. Like other chemotaxis pathways, pili-mediated surface sensing results in a transient response amplified by a positive feedback that increases type IV pili activity, thereby promoting long-term surface attachment that can stimulate additional virulence and biofilm-inducing pathways. The methyl-accepting chemotaxis protein-like chemosensor PilJ directly interacts with the major pilin subunit PilA. Our results thus support a mechanochemical model where a chemosensory system measures the mechanically induced conformational changes in stretched type IV pili. These findings demonstrate that P. aeruginosa not only uses type IV pili for surface-specific twitching motility, but also as a sensor regulating surface-induced gene expression and pathogenicity.</p>

DOI10.1073/pnas.1502025112
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID26041805
PubMed Central IDPMC4475988
Grant ListP30 DK072517 / DK / NIDDK NIH HHS / United States
R01 AI065302 / AI / NIAID NIH HHS / United States