资源描述:
《Formation of Nuclear Bodies of Arabidopsis CRY2 in Response to Blue Light Is Associated with Its Blue Light–Dependent Degradation W英文资料》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、ThePlantCell,Vol.21:118–130,January2009,www.plantcell.orgã2009AmericanSocietyofPlantBiologistsFormationofNuclearBodiesofArabidopsisCRY2inResponsetoBlueLightIsAssociatedwithItsBlueLightDependentDegradationWXuhongYu,a,1,2RicardoSayegh,a,1MaskitMaymon,aKatherineWarpeha,bJohnKlejnot,aHongyunYang,aJi
2、eHuang,aJanetLee,aLonKaufman,bandChentaoLina,3aDepartmentofMolecular,Cell,andDevelopmentalBiology,UniversityofCalifornia,LosAngeles,California90095bDepartmentofBiologicalSciences,LabforMolecularBiology,UniversityofIllinois,Chicago,Illinois60607Arabidopsisthalianacryptochrome2(CRY2)mediatesphotop
3、eriodicpromotionoffloralinitiationandbluelightinhibitionofhypocotylelongation.IthasbeenhypothesizedthatphotoexcitationderepressesCRY2bydisengagingitsC-terminaldomainfromtheN-terminalPHRdomain.Totestthishypothesis,weanalyzedactivitiesofCRY2fusedtogreenfluorescentprotein(GFP)ateithertheNterminus(GFP
4、-CRY2)ortheCterminus(CRY2-GFP).WhileGFP-CRY2exertslight-dependentbiochemicalandphysiologicalactivitiessimilartothoseoftheendogenousCRY2,CRY2-GFPshowedconstitutivebiochemicalandphysiologicalactivities.CRY2-GFPisconstitutivelyphosphorylated,itpromotesdeetiolationinbothdarkandlight,anditactivatesflo
5、ralinitiationinbothlong-dayandshort-dayphotoperiods.TheseresultsareconsistentwiththehypothesisthatphotoexcitedCRY2disengagesitsC-terminaldomainfromthePHRdomaintobecomeactive.Surprisingly,wefoundthatCRY2-GFP,butnotGFP-CRY2,formeddistinctnuclearbodiesinresponsetobluelight.ComparedwithGFP-CRY2orthe
6、endogenousCRY2,CRY2-GFPdegradationwassignificantlyretardedinresponsetobluelight,suggestingthatthenuclearbodiesmayresultfromaccumulationofphotoexcitedCRY2-GFPwaitingtobedegraded.Consistentwiththisinterpretation,weshowedthatbothGFP-CRY2andendogenousCRY2formednuclearbodiesinthepresenceofthe26S-prote
7、asomeinhibitorsthatblockbluelightdependentCRY2degradation.INTRODUCTIONearlystagesofsignaltransductioninvolvingplantcryptochromesareassociatedwithseveraldifferentmolecularevents.ForCryptochromesarebluelightreceptorsthatmediat