植物生理與分子生物學(xué)：光控發(fā)育與光信號(hào)轉(zhuǎn)導(dǎo)

光控發(fā)育與光信號(hào)轉(zhuǎn)導(dǎo)TherolesoflightinthelifeofplantsPhotomorphogenesisisreferringtotheresponseofplanttolight,whichisthecentralthemeinplantdevelopment.PhotomorphogenesisReception…Transduction…ResponseCELLWALLCYTOPLASM

1Reception

2Transduction

3ResponseReceptorRelaymoleculesActivationofcellularresponsesHormoneorenvironmentalstimulusPlasmamembraneReception:Internalandexternalsignalsaredetectedbyreceptors(proteinsthatchangeinresponsetospecificstimuli)Transduction:SecondmessengerstransferandamplifysignalsfromreceptorstoproteinsthatcausespecificresponsesResponse:Resultsinregulationofoneormorecellularactivities.InmanycasesthisinvolvestheincreasedactivityofcertainenzymesphyA,phyCphyB,D,EPHOT1,PHOT2MovementresponsesGrowthRegulationPhotoperiodismPlantphotoreceptorsCRY1,CRY2FKF,ZTLUVR8Photoreceptor

A.lightabsoptionB.lightresponselightdependentproteininteractionlightregulatedexpression

lightdependentproteinre-localizationlightrelatedphysilogicalphenotypeC.photoperceptionmechanismcry2WTcry1WTCryptochrome(CRY)istheonlyphotoreceptororcriticalcomponentofthecircadianclockcurrentlyknowntofunctioninallthreeevolutionarylineages,frombacteriatoplantsandanimals.

Nature1993cry1WTHY4BluelightCRY1OXWTBluelightAnthonyR.CashmoreUniversityofPennsylvaniaHeisbestknownforidentifyingplantphotoreceptorproteinscalledcryptochromes,whichenableplantsandanimalstotellcircadiantime.ArabidopsisCRY1andCRY2primarilyregulatebluelightinhibitionofstemelongationandphotoperiodinductionoffloralinitiation,respectively.cry2WTcry1WTWTcry1WTcry2

CRY2regulatesphotoperiodicfloweringinArabidopsis(YanovskyandKay,2002Nature419:308)(Valverdeetal.,2004,Science303:1003)PhotoperiodismandControlofFloweringFloweringinmanyspeciesrequiresacertainphotoperiodShort-dayplants(generallyflowerinlatesummer,fall,orwinter)Long-dayplants(flowerinlatespringorearlysummer)(lettuce…iris)Day-neutralplantsareunaffectedbyphotoperiodandfloweratacertainstageofmaturityregardlessofdaylengthatthetime(tomato…dandelion)TheEffectofLightontheBiologicalClockPhotoperiod,therelativelengthsofnightanddayistheenvironmentalstimulusplantsusemostoftentodetectthetimeofyearPhotoperiodismIsaphysiologicalresponsetophotoperiodCryptochrome，Phytochrome–clockentrainmentBiologicalClocksandCircadianRhythmsManyplantprocessesoscillateduringthedayForexample,manylegumeslowertheirleavesintheeveningandraisetheminthemorning(thesearecalledsleepmovements)NoonMidnightCircadianrhythmscyclicalresponsestoenvironmentalstimuliapproximately24hourslongcanbeentrained(set)toexactly24hoursbytheday/nightcyclebydailysignalsfromtheenvironmentHumanexamplesinclude:bloodpressure,bodytemperature,alertness,metabolicrate,etc.etc.PhytochromesandCryptochromesintheEntrainmentofthe

ArabidopsisCircadianClockWTandphyainblue(A)orredlight(B)WTandcry1(A)orcry2(B)inbluelightTheCTerminiofArabidopsisCryptochromesMediateaConstitutiveLightResponse

Yangetal,Cell2000GUS-CCT2andGFP-N563arebothactiveinvivo--why?GUS-CCT2andGFP-N563overlayby80residues-calledNC80CRY2GUS-CCT2G-N563GUS-NC80GFP-CCT2Yuetal,PNAS2007Blue-light-dependentphosphorylationofArabidopsisCRY2Blue-light-dependentphosphorylationofArabidopsisCRY1Shalitinetal,Nature2002;PlantCell2003Blue-light-dependentdegradationofArabidopsisCRY2Whatproteinsdocryptochromesinteract?ConclusionandquestionArabidopsiscaseinkinase1proteinsCK1.3andCK1.4phosphorylatecryptochrome2toregulatebluelightsignaling.Tanetal,PlantCell2013.YangHetal.PlantCell2001;13:2573-2587?2001byAmericanSocietyofPlantBiologistsArabidopsisCRY1BindstoCOP1inYeastinBothBlueLightandDark.TheCOP1(constitutivephotomorphogenic1)protein,comprisingRINGfinger,coiled-coilandWD40domainsCRY2actsonlyinthenucleusNuclearimmunostainofCRY2CRY2-GRisactiveonlyinthepresenceofdexYuetal,PlantCell2007CRY2completesitspost-translationallifecycleinthenucleusYuetal.,2007,PlantCell19:3146-3156

PeterQuailUniversityofCalifornia,BerkeleyphyAmutantseedlingsshowreducedsensitivity

tofar-redlightphyBmutantseedlingsshowreduced

sensitivitytoredlightPhytochromeBactsasaredlightsensorPhytochromeAbsorptionPhytochromeisencodedbyamultigenefamilyPhyA→responsestoFRPhyB→responsestoRorwhitelightPre-dominantformsHaveuniquerolesinregulatingresponsestoredandfar-redPhytochromeswitchPhytochromesexistintwophotoreversiblestates(isomers)withconversionofPr(redabsorbing)toPfr(far-redabsorbing)triggeringmanydevelopmentalresponsesWhenseedsareexposedtoadequatesunlightforthefirsttime,itistheappearanceofPfrthattriggersgerminationSynthesisFar-redlightRedlightSlowconversionindarkness(someplants)Responses:seedgermination,controlofflowering,etc.EnzymaticdestructionPfrPrFigure1.PIF3cDNAIdentificationandInteractionwithBothphyAandphyBC-TerminalDomains1998CellPIF4regulatesIAAabundanceandactivityathightemperature.PNAS|December13,2011PIF4regulatestheauxinbiosynthesisgenesTAA1andCYP79B2andbindstotheirpromotersinatemperature-dependentmanner.PLoSGenetics,March2012LossofPIF4FunctionDisruptstheHighTemperature–InducedElevationofYUC8TranscriptsandFreeIAALevels.TranscriptionfactorPIF4controlsthethermosensoryactivationoffloweringKumaretal,Nature2012NucleusaccumulationofPHYBdependsonRedlighttreatmentPIF3actsasatransportfacilitatorforphyBnuclearimportinvitro.PNAS|April10,2012|vol.109PHYAgetdegradedthroughtheproteasomepathwayundertheredlightcondition

Phototropism

WinslowBriggs

DepartmentofPlantBiology

CarnegieInstitutionforSciencePlantcell1995MutationsintheNPH1LocusofArabidopsisDisruptthePerceptionofPhototropicStimuliScience1998

ArabidopsisNPH1:AFlavoproteinwiththePropertiesofaPhotoreceptorforPhototropism

chloroplastmovementstomataopening

DemarsyEetal.TheEMBOJournal(2012),1–11PKS4isanintegrationpointbetweenphototropinandphytochromesignallingPhytochromeKinaseSubstrate4isphosphorylatedbythephototropin1photoreceptorTheDomainStructuresofZTL/FKF1/LKP2andRelatedProteins,AminoAcidSequenceAlignmentsofLOVDomains,andPhotochemicalPropertiesofPhototropinandFKF1LOVDomains.(A)SchematicillustrationoffunctionaldomainsofZTL/FKF1/LKP2familyproteins,phototropinproteins,andPAS/LOVproteins.ItoSetal.Mol.Plant2012;mp.sss013?TheAuthor2012.PublishedbytheMolecularPlantShanghaiEditorialOfficeinassociationwithOxfordUniversityPressonbehalfofCSPBandIPPE,SIBS,CAS.Cell2000ZEITLUPEEncodesaNovelClock-AssociatedPASProteinfromArabidopsis

TheScrippsResearchInstituteUCSDUSCCell2000FKF1,aClock-ControlledGenethatRegulatestheTransitiontoFloweringinArabidopsisBonnieBartel*RiceUniversitfkf1HasMildClockDefectsbutStronglyEnhancesztlPhenotype.Plantcell2010Nature2007

ZEITLUPEisacircadianphotoreceptorstabilizedbyGIGANTEAinbluelight.

ZTLinteractwithGIinabluelightdependentmannerandtheystabilizeeachotherinthebluelightScience2007FKF1andGIGANTEAComplexFormationIsRequiredforDay-LengthMeasurementinArabidopsisFKF1interactswithGIinablue-light–dependentmanner.Nature2003TargeteddegradationofTOC1byZTLmodulatescircadianfunctioninArabidopsisthalianaFKF1bindstotheCDF1protein,whichaffectsfloweringtime.Science309:2952005Science336:10472012FKF1interactswithCOthroughitsLOVdomain,andbluelightenhancesthisinteraction.Light-MediatedProteolysisControlledbyZTL,FKF1,andLKP2intheRegulationofFloweringTimeandtheCircadianClock.(A)ThefunctionofFKF1inthecontroloffloweringtime.ItoSetal.Mol.Plant2012;mp.sss013?TheAuthor2012.PublishedbytheMolecularPlantShanghaiEditorialOfficeinassociationwithOxfordUniversityPressonbehalfofCSPBandIPPE,SIBS,CAS.TentativeStructureChangesofFKF1TriggeredbyBlue-LightAbsorption.(A)Proposedstructuralchangesofphot1.ItoSetal.Mol.Plant2012;mp.sss013?TheAuthor2012.PublishedbytheMolecularPlantShanghaiEditorialOfficeinassociationwithOxfordUniversityPressonbehalfofCSPBandIPPE,SIBS,CAS.uvr8-1ishypersensitivetoUV-Bincomparisonwithwild-typeLer.KliebensteinDJetal.PlantPhysiol.2002;130:234-243?2002byAmericanSocietyofPlantBiologistsScience1April2011PerceptionofUV-BbytheArabidopsisUVR8ProteinLucaRizzini1,*

Jean-JacquesFavory,*CatherineCloix,DavideFaggionato,AndrewO’Hara,EiriniKaiserli,RalfBaumeister,EberhardSch?fer,FerencNagy,GarethI.Jenkins,andRomanUlm,?

Nature|Article2012Structuralbasisofultraviolet-BperceptionbyUVR8DiWu1*,QiHu1*,ZhenYan1*,WenChen2,ChuangyeYan3,XiHuang2,4,JingZhang1,PanyuYang2,4,HaitengDeng1,JiaweiWang3,XingWangDeng2,4&YigongShi1Science2012PlantUVR8PhotoreceptorSensesUV-BbyTryptophan-MediatedDisruptionofCross-DimerSaltBridgesJohnM.Christie,1,2AndrewS.Arvai,2KatherineJ.Baxter,1*MonikaHeilmann,1*AshleyJ.Pratt,2AndrewFigure4.TheCOP1proteinactsascentralswitchinArabidopsislight-controlleddevelopment

CRY2signalingpartnerCIB1

HongtaoLiu中國科學(xué)院上海生命科學(xué)院植物生理生態(tài)研究所

AphotoreceptormayinteractwithitstargetproteinbytwoalternativemodesofactionsAphotoreceptormayinteractwithitstargetinresponsetolight,leadingtolight-dependentphysiologicalresponse.Aphotoreceptormayalternativelyinteractwithatargetprotein,butonlythephotoexcitedphotoreceptortrigerschangesofbiochemicalactivitiesassociatedwithtargetproteins.CIB1(CRY2-interactingbHLH)specificallyinteractswithCRY2inbluelight（TheCRY2D387AmutantproteinlacksFADanditis“blind”）（CRY2D387AdoesnotbindtoCIB1）(C-D)Invitropull-downassaysshowinginteractionbetweenCRY2andCIB1underbluelightorredlight(E)Histidineauxotrophyassayshowinglight-independentinteractionbetweenCRY2andCOP1,andbetweenCRY2D387AandCOP1.CRY2interactswithCIB1invivo(+MG132)CIB1showshighaffinitytoG-boxinvitroCIB1actsasabluelight-andCRY-dependenttranscriptionregulatorinArabidopsiscellsCIB1mayactredundantlywithotherbHLHproteinstopromotefloralinitiationCIB1promotesfloralinitiationinaCRY2-dependentmannerCIB1promotesFTexpressionCIB1promoterisactiveinthevascularbundlecellswhereCRY2activatesFTexpressionCIB1bindstothechromatinregionoftheFTpromoterthatcontainsE-boxCIB1(CRY2-interactingbHLH)CIB1interactswithCRY2inabluelight–specificandFAD-dependentmannerinyeastCIB1isanuclearproteinandCIB1interactswithCRY2inArabidopsiscellsCIB1bindstoGbox(CACGTG)invitrowithahigheraffinitythanitsinteractionwithotherE-boxelements(CANNTG).CIB1isatranscriptionregulatorandtheactivityisatleastpartiallydependentonbluelightandCRY2.CIB1actstogetherwithadditionalCIB1-relatedproteinstopromoteCRY2-dependentfloralinitiation.CIB1stimulatesFTmessengerRNAexpression,anditinteractswithchromatinDNAoftheFTgenethatpossessesvariousE-boxelementsexceptGbox.Wehypothesizethatthebluelight–dependentinteractionofcryptochrome(s)withCIB1representsanearlyphotoreceptorsignalingmechanisminplants(Liuetal.,2008Science,322:1535).(Liuetal.,Science,322:1535)CRY2InteractswithSPA1inResponsetoBlueLightThebluelight-inducedcolocalization(indicatedbyyellowspots)ofCRY2(red)orMyc-SPA1(green）TheCRY2-SPA1InteractionEnhancestheCRY2-COP1InteractioninResponsetoBlueLightBluelightregulationofCIB1proteolysisinArabidopsis

ThetranscriptionofCIB1islightregulated.CIB1isdegradedintheabsenceofbluelightWesternblotofseedlingstransferredfrombluelightorcontinuewhitelighttodark,redlightorfarredlight.CIB1proteinaccumulatesinthebluelightTimecourseofCIB1accumulationinresponsetobluelightFluenceratedependentaccumulationofCIB1proteinImmunoblotshowingCIB1proteinlevelinseedlingsexposedtodifferentfluencerateofbluelightfortheindicatedduration.(B)QuantificationofCIB1levelsin(A).ABCIB1degradationisdependentonthe26SproteasomeInhibitionofCIB1degradationbytheproteasomeinhibitorMG1-32.SeedlingsgrowinthecontinuewhitelightwereexcisedandincubatedwithMG1-32ormocksolutionandthenmovetodark.CRYsarenotthephotoreceptormediatingbluelightsuppressionofCIB1degradationImmunoblotshowingCIB1proteinlevelinseedlingsmovefromredlighttobluelightoroppositeinWTorcry1cry2mutantbackgroundphyAisnotthephotoreceptormediatingbluelightsuppressionofCIB1degradationImmunoblotshowingCIB1proteinlevelinseedlingsmovefromredlighttobluelightoroppositeinWTorcry1cry2phyAmutantbackgroundphotsarenotthephotoreceptormediatingbluelightsuppressionofCIB1degradationImmunoblotshowingCIB1proteinlevelinseedlingsmovefromredlighttobluelightoroppositeinWTorcry1cry2phot1phot2mutantbackgroundLossofZTLorLKP2seemstoenhanceCIB1degradation

Red

BlueZTLactsasthephotoreceptormediatingbluelightsuppressionofCIB1degradationCIB1proteinisclockregulatedCIB1promotesfloralinitiationinaFKF-independentbutZTL,LKP2-dependentmannerCOP1isnottheE3ubiquitinligaseforCIB1degradationLiuetal,PNAS2013

Summary1.CIB1proteinexpressionisregulatedspecificallybybluelight.CIB1proteinisdegradedintheabsenceofbluelight.2.CIB1isdegraded,viaaubiquitin/proteasomepathway,inthedark,red,andFRlight3.ZTLbutnotCRYisthephotoreceptorthatregulatethisbluelightspecificstabilizationofCIB1.ThefunctionofmultiplebHLHproteinsinCRY2signaltransductionPhylogeneticanalysisofthebHLHdomainsequencespermitsclassificationof147bHLHgenesinto21subfamilies.CRY2interactswithseveralCIB1relatedbHLHproteinsCIB4,CIB5promotefloralinitiationinaCRY2-dependentmannerCIB3,CIL1promotefloralinitiationCIB2,CIL2donotpromotefloralinitiationTheCIB1-EARfusionproteinsuppressesFTexpressionandfloralinitiation(PlantCell,2001,13:1959)

TheEARsuppressormotifCIB1-EARinteractswithCRY2inabluelightdependentmanner

TheCIB4,5-EARfusionproteinsuppressesfloralinitiationCIB1,3,4,5affectFTexpressionRelativeexpression(FT/ACT)

CIB3,CIB4andCIB5(Green)allco-localizewithCRY2(Red)inthenucleus.CRY2-CIB1/2/5interactioninPlantcellsBluelight-dependentCRY2-CIB5interactioninPlantcellsCIB4andCIB5canbothbindtoFTchromatin

CIB2,CIB4andCIB5(Green)allco-localizewithCIB1(Red)inthenucleus.CIB1interactwithotherCIBsinvivoCIB3,4andCIB5showhighaffinitytoG-boxinvitroCIB3,4andCIB5showverylowaffinitytomutatedG-box(E-box)invitroCIB1hassimilaractivityonGbox(CACGTG)andE(CANNTG)boxinArabidopsiscellsFTE-boxmutantcontrolHeterodimerizationaffecttheDNAbindingaffinityofthetranscriptionfactorTransientassaysshowCIBs(CIB1/2/4/5)activationoftheFTpro::LUCreportergene.

LiuYetal,PlosGenetics2013CIB1,4,5aredegradedintheabsenceofbluelight&accumulateinthebluelightCIB1,4,5aredegradedintheabsenceofbluelight&accumulateinthebluelightCIB1,3,4,5aredegradedintheabsenceofbluelightCIB1,4,5degradationaredependentonthe26Sproteasome

SummaryCIB1actstogetherCIB3,4,5topromoteCRY2-dependentfloralinitiation.CIB5interactswithCRY2inabluelightdependentmannerinArabidopsiscellsCIB4,5bindstoGbox(CACGTG)invitrowithahigheraffinitythanitsinteractionwithotherE-boxelements(CANNTG).CIB4,5stimulatesFTmessengerRNAexpression,andtheyinteractwithchromatinDNAoftheFTgenethatpossessesvariousE-boxelementsexceptGbox.CIB1,4;CIB4,5Heterodimerizationhave