很多細(xì)菌利用群體感應(yīng)來進行細(xì)胞與細(xì)胞之間的通信,，從而對基因表達(dá)實施依賴于種群數(shù)量的控制。這個過程中所涉及的信號分子通常為acyl-homoserine lactones (acyl-HSLs),，它們與脂肪酸基團相結(jié)合,，來通過在不同亞組基因上發(fā)揮作用的一系列不同信號受體提供特異性。目前只有少數(shù)這種信號已知,，但在光合作用細(xì)菌Rhodopseudomonas palustris中所發(fā)現(xiàn)的HSL主題上的一個新變化表明,，也許存在更多這種信號。該細(xì)菌用一種與脂肪性acyl-HSL合成酶相似的酶來從環(huán)境p-香豆酸生成p-coumaroyl-HSL,，而不是利用來自細(xì)胞內(nèi)的脂肪酸,。該細(xì)菌有一個信號受體,，它通過對p-coumaroyl-HSL做出反應(yīng)來全面調(diào)控基因表達(dá)。其他種類的細(xì)菌也制造p-coumaroyl-HSL,，所以可能存在環(huán)境條件下的種內(nèi)通信,。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 454, 595-599 (24 July 2008) | doi:10.1038/nature07088; Received 18 April 2008;
A new class of homoserine lactone quorum-sensing signals
Amy L. Schaefer1, E. P. Greenberg1, Colin M. Oliver2, Yasuhiro Oda1, Jean J. Huang1, Gili Bittan-Banin1, Caroline M. Peres3, Silke Schmidt4, Katarina Juhaszova1, Janice R. Sufrin2 & Caroline S. Harwood1
1 Department of Microbiology, University of Washington, Washington 98195, USA
2 Molecular Pharmacology and Cancer Therapeutics Program, Roswell Park Cancer Institute, State University of New York at Buffalo, Buffalo, New York 14263, USA
3 Danisco Genencor, Palo Alto, California 94304, USA
4 Institute of Molecular Biosciences, University of Frankfurt, Frankfurt 60438, Germany
Correspondence to: Caroline S. Harwood1 Correspondence and requests for materials should be addressed to C.S.H. (Email: [email protected]).
Abstract
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.
