A new class of homoserine lactone quorum-sensing signals.
Quorum sensing is a term used to describe cell-to-cell communication that allows cell-density-dependent gene expression. Many bacteria use acyl-homoserine lactone (acyl-HSL) synthases to generate fatty acyl-HSL quorum-sensing signals, which function with signal receptors to control expression of specific genes. The fatty acyl group is derived from fatty acid biosynthesis and provides signal specificity, but the variety of signals is limited. Here we show that the photosynthetic bacterium Rhodopseudomonas palustris uses an acyl-HSL synthase to produce p-coumaroyl-HSL by using environmental p-coumaric acid rather than fatty acids from cellular pools. The bacterium has a signal receptor with homology to fatty acyl-HSL receptors that responds to p-coumaroyl-HSL to regulate global gene expression. We also found that p-coumaroyl-HSL is made by other bacteria including Bradyrhizobium sp. and Silicibacter pomeroyi. This discovery extends the range of possibilities for acyl-HSL quorum sensing and raises fundamental questions about quorum sensing within the context of environmental signalling.
Department of Microbiology, University of Washington, Washington 98195, USA.
Amy L
AL
Schaefer
E P
EP
Greenberg
Colin M
CM
Oliver
Yasuhiro
Y
Oda
Jean J
JJ
Huang
Gili
G
Bittan-Banin
Caroline M
CM
Peres
Silke
S
Schmidt
Katarina
K
Juhaszova
Janice R
JR
Sufrin
Caroline S
CS
Harwood
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001483:Base Sequence; D001681:Biological Assay; D003373:Coumaric Acids / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D053038:Quorum Sensing; D018085:Regulon; D012241:Rhodopseudomonas / Q000201:enzymology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction
D001426:Bacterial Proteins; D003373:Coumaric Acids; C088386:homoserine lactone; D015107:4-Butyrolactone