Oxazaborolidine derivatives inducing autoinducer-2 signal transduction in Vibrio harveyi.
The bioluminescence of the marine bacterium Vibrio harveyi is controlled by quorum sensing. This effect is mediated by production, accumulation, and auto-detection of the species-specific autoinducer 1 (AI-1), autoinducer 2 (AI-2), and the V. cholerae autoinducer 1 (CAI-1). The V. harveyi AI-2 was recently identified as furanosyl borate diester. We synthesized several oxazaborolidine derivatives that chemically resemble the structure of AI-2. Five oxazaborolidine derivatives (BNO-1 to BNO-5) were tested, however only BNO-1 (3,4-dimethyl-2,5-diphenyl-1,3,2-oxazaborolidine), and BNO-5 (2-butyl-3,4-dimethyl-5-phenyl-1,3,2-oxazaborolidine) strongly induced V. harveyi bioluminescence in V. harveyi mutant (BB170) lacking sensor 1. A dose-dependent relationship between those oxazaborolidine derivatives and bioluminescence induction was observed with this V. harveyi strain (BB170). BNO-1 and BNO-5 did not affect V. harveyi BB886 lacking sensor 2. Using a mutant strain which produces neither AI-1 nor AI-2 (V. harveyi MM77) we showed that the presence of spent medium containing AI-2 is essential for BNO-1 and BNO-5 activity. This effect was similar when introducing the spent medium and the BNOs together or at a 3-h interval. A comparable induction of bioluminescence was observed when using synthetic DPD (pre-AI-2) in the presence of BNO-1 or BNO-5. The mode of action of BNO-1 and BNO-5 on bioluminescence of V. harveyi is of a co-agonist category. BNO-1 and BNO-5 enhanced AI-2 signal transduction only in the presence of AI-2 and only via sensor 2 cascade. BNO-1 and BNO-5 are the first oxazaborolidines reported to affect AI-2 activity. Those derivatives represent a new class of borates which may become prototypes of novel agonists of quorum sensing mediated by AI-2 in V. harveyi.
Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem 91120, Israel.
R
R
Aharoni
M
M
Bronstheyn
A
A
Jabbour
B
B
Zaks
M
M
Srebnik
D
D
Steinberg
D001426:Bacterial Proteins; D001896:Boron Compounds / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry / Q000494:pharmacology*; D006714:Homoserine / Q000031:analogs & derivatives* / Q000187:drug effects; D007783:Lactones; D049449:Luminescence; D010080:Oxazoles / Q000737:chemistry / Q000494:pharmacology*; D053038:Quorum Sensing; D015398:Signal Transduction / Q000187:drug effects*; D013329:Structure-Activity Relationship; D014733:Vibrio / Q000187:drug effects*
D001426:Bacterial Proteins; D001896:Boron Compounds; D006573:Heterocyclic Compounds, 1-Ring; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D010080:Oxazoles; D006714:Homoserine