Switch of SpnR function from activating to inhibiting quorum sensing by its exogenous addition

Journal Article · Fri Sep 02 04:00:00 EDT 2016 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2016.07.017· OSTI ID:22606197

Takayama, Yuriko ^[1]; Kato, Norihiro ^[2]

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1. Department of Innovation Systems Engineering, Graduate School of Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)
2. CREST, Japan Science and Technology Agency, 7-1-2 Yoto, Utsunomiya, Tochigi 321-8585 (Japan)

The opportunistic human pathogen Serratia marcescens AS-1 produces the N-hexanoylhomoserine lactone (C6HSL) receptor SpnR, a homologue of LuxR from Vibrio fischeri, which activates pig clusters to produce the antibacterial prodigiosin. In this study, we attempted to artificially regulate quorum sensing (QS) by changing the role of SpnR in N-acylhomoserine lactone (AHL)-mediated QS. SpnR was obtained as a fusion protein tagged with maltose-binding protein (MBP) from overexpression in Escherichia coli, and its specific affinity to C6HSL was demonstrated by quartz crystal microbalance analysis and AHL-bioassay with Chromobacterium violaceum CV026. Prodigiosin production was effectively inhibited by externally added MBP-SpnR in both wild-type AS-1 and the AHL synthase-defective mutant AS-1(ΔspnI). For the mutant, the induced amount of prodigiosin was drastically reduced to approximately 4% with the addition of 18 μM MBP-SpnR to the liquid medium, indicating 81% trapping of C6HSL. A system for inhibiting QS can be constructed by adding exogenous AHL receptor to the culture broth to keep the concentration of free AHL low, whereas intracellular SpnR naturally functions as the activator in response to QS. - Highlights: • Quorum sensing (QS) regulates the expression of some bacterial genes. • We added an AHL receptor to culture media to inhibit QS in Serratia marcescens AS-1. • The exogenous receptor effectively bound C6HSL and inhibited QS. • This approach can be used to artificially regulate AHL-mediated QS.

• OSTI ID: 22606197
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 4 Vol. 477; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BIOASSAY
CULTURE MEDIA
ESCHERICHIA COLI
LACTONES
MALTOSE
MBP
MICROBALANCES
MUTANTS
PATHOGENS
QUARTZ
RECEPTORS
SERRATIA
SWINE