Chapter Ten Global Regulation

《Chapter Ten Global Regulation》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、ChapterTenGlobalRegulation:RegulonsandStimulons1.Overview2.StressResponsesinBacteria3.RegulationofVirulenceGenesinPathogenicBacteria4.QuorumSensing5.Biofilm1.Overview•GlobalRegulation:SimultaneousRegulationofNumerousOperonsinResponsetoMajorEnvironmentalChanges•Regulon:AlargenumberofOperonsun

2、dertheControlofaSingleRegulatoryProtein•Stimulon:TheCollectionofRegulonsthatrespondtothesameenvironmentalConditions2.StressResponsesinBacteriaExtracytoplasmic(Envelope)StressResponses•Cpxpathway•SigmaFactorECpxpathwayATwo-componentSensor-KinaseResponse-Regulatorsystem
Two-componentsystemsser

3、veasabasicstimulus-responsecouplingmechanismtoalloworganismstosenseandrespondtochangesinmanydifferentenvironmentalconditions.Theytypicallyconsistofamembrane-boundhistidinekinasethatsensesaspecificenvironmentalstimulusandacorrespondingresponseregulatorthatmediatesthecellularresponse,mostlythr

4、oughdifferentialexpressionoftargetgenes.Twocomponentsignalingsystemsarewidelyoccurringinprokaryoteswhereasonlyafewtwo-componentsystemshavebeenidentifiedineukaryoticorganismsCpxpathway•CpxA-CpxRSigmaFactorEAnti-SigmaFactorSigmaFactor3.RegulationofVirulenceGenesinPathogenicBacteria•Salmonellae

5、ntericaserovarTyphi•90MillionPeopleInfectedEachYear•TyphoidFeverHostDefenseSystemNaturalBarriersSalmonellaSurvivalStrategieswithintheHostStomach•pHHomeostaticSystems•SynthesisofAcidShockProteins(ASPs)•ModificationsoftheMembraneCompositionHostDefenseSystemMacrophageSalmonellaSurvivalStrategie

6、s---VirulenceFactorsTypeIIISecretionSystemSalmonellaVirulenceFactorsSalmonellaPathogenicityIslandsSPI1SPI2InductionofUptakeInhibitionofPhagosomeMaturation4.QuorumSensing•Quorumsensingisasystemofstimulusandresponsecorrelatedtopopulationdensity.•Manyspeciesofbacteriausequorumsensingtocoordinat

7、egeneexpressionaccordingtothedensityoftheirlocalpopulation.QuorumSensingVibrio.fischeriBobtailSquidluxCDABELuciferaseGram-negativeBacteria:HSLGram-positiveBacteria:Peptides5.Biofilm•Abiofilmisanaggregateofmicroorganismsinwhichcellsadheretoeachother