Multiple signalling systems controlling expression of luminescence in Vibrio harveyi: sequence and function of genes encoding a second sensory pathway.
Density-dependent expression of luminescence in Vibrio harveyi is regulated by the concentration of extracellular signal molecules (autoinducers) in the culture medium. One signal-response system is encoded by the luxL,M,N locus. The luxL and luxM genes are required for the production of an autoinducer (probably beta-hydroxybutyl homoserine lactone), and the luxN gene is required for the response to that autoinducer. Analysis of the phenotypes of LuxL,M and N mutants indicated that an additional signal-response system also controls density sensing. We report here the identification, cloning and analysis of luxP and luxQ, which encode functions required for a second density-sensing system. Mutants with defects in luxP and luxQ are defective in response to a second autoinducer substance. LuxQ, like LuxN, is similar to members of the family of two-component, signal transduction proteins and contains both a histidine protein kinase and a response regulator domain. Analysis of signalling mutant phenotypes indicates that there are at least two separate signal-response pathways which converge to regulate expression of luminescence in V. harveyi.
Bassler
B L
BL
Agouron Institute, La Jolla, California 92037.
Wright
M
M
Silverman
M R
MR
D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D015964:Gene Expression Regulation, Bacterial; D008163:Luminescent Measurements; D008954:Models, Biological; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010641:Phenotype; D010766:Phosphorylation; D010770:Phosphotransferases; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011499:Protein Processing, Post-Translational; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000502:physiology*; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology; D014733:Vibrio / Q000235:genetics / Q000502:physiology*
D001426:Bacterial Proteins; C088907:LuxO protein, Vibrio harveyi; C090749:LuxP protein, Vibrio; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C084289:luxL protein, Vibrio harveyi; C084288:luxM protein, Vibrio harveyi; C064778:LuxR autoinducer binding proteins; C030654:N-(3-oxohexanoyl)-3-aminodihydro-2(3H)-furanone; D010770:Phosphotransferases; D011494:Protein Kinases; C084290:luxN protein, Vibrio harveyi; C090750:luxQ protein, Vibrio harveyi; D015107:4-Butyrolactone