title: Methods for analysis of bacterial autoinducer-2 production.
abstract: Quorum sensing is a cell-cell signaling process that many bacteria use to regulate gene expression as a function of the density of the population. This phenomenon involves the production, release, and response to small chemical molecules termed autoinducers. Most autoinducers are species-specific; however, one autoinducer called autoinducer-2 (AI-2) is produced and detected by many species of bacteria and thus can foster inter-species communication. This unit describes two assays to detect and quantify AI-2 from biological samples. The first uses a bacterial reporter strain, which produces bioluminescence in response to AI-2. The second is an in vitro assay based on a modified version of an AI-2 receptor fused to a cyan fluorescent protein and a yellow fluorescent protein. Binding of AI-2 to this fusion protein induces a dose-dependent decrease in fluorescence resonance energy transfer (FRET), enabling quantification of the AI-2 concentration in the samples.
authors: Department of Plant and Microbial Biology, University of California, Berkeley, California, USA.
authors: Michiko E
authors: ME
authors: Taga
authors: Karina B
authors: KB
authors: Xavier
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000378:metabolism*; D001681:Biological Assay / Q000379:methods*; D049071:Endopeptidase Clp / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D017930:Genes, Reporter; D006714:Homoserine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D007783:Lactones / Q000032:analysis* / Q000378:metabolism; D011485:Protein Binding; D053038:Quorum Sensing
chemical_list: C483566:ClpYQ protease, E coli; D029968:Escherichia coli Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D006714:Homoserine; D049071:Endopeptidase Clp