蛋白质分选下课件

Chapter7ProteinsortingII------free-ribosomesystemsecretorypathway

1.1SynthesisandTargetingofMitochondrial线粒体具有1000多种蛋白质，其自身合成的仅十余种，因此大量蛋白质是在细胞质中合成的。MatrixOutermembraneIntermembranespaceCrosssectionofmitochondrionInnermembraneMitochondrialProteinsThatAreSynthesizedintheCytosolProteinsAreTargetedtoSub-mitochondrialCompartmentsProteinTransportintoInnerMembraneandIntermembraneSpaceRequiresTwoSignalSequences线粒体转运与叶绿体非常相似1.2SorttoChloroplastCompartmentImportofrubiscosmall(S)subunitsintothechloroplaststroma

转运肽内囊体膜蛋白转运需要两段信号1.3SynthesisandTargetingofPeroxisomeProteins

核基因合成，后转运方式运输1.4ProteinsorttonucleusThenuclearporecomplex0.1um

SideviewofnuclearporeMechanismofproteinimportProteinsselectedforimportintonucleushaveanuclearlocalizationsignal(NLS)e.g.-Pro-Pro-Lys-Lys-Lys-Arg-NLSisrecognizedbycytosolicnuclearimportreceptorswhichbindtonuclearporefibrilsextendingintocytosolPoreopensandproteinplusimportreceptorenternucleus.Importreceptorexportedforre-useNuclearlocalizationsignals

Nuclearlocalisationsignal(NLS)Nucleoplasminlabelandinjection

NucleoplasminlocationeffectProteintransportbynucleusporecomplexTransportisselectiveRestricttransportparticleRequireenergyexpendituresaturateddynamicTransportisdoubledirectionImportandexport1.4.2MechanismofexportfromnucleusMostoftrafficmovingoutofnucleusconsistsofdifferenttypesofRNAmoleculesRNAmovesthroughnuclearporeascomplexofribonucleoprotein(RNP):核糖核蛋白颗粒ProteincomponentofRNPcontainsanuclearexportsignal(NES)thatisrecognisedbyexportproteinsmRNAisboundbyhnRNPonlyafterfullysplicedsoonlymatureRNAisexportednuclearRNAandproteinexport

◆mRNAexport●核内不均一核糖核蛋白(heterogeneousribonucleoprotein,hnRNP)●信使RNP(messengerRNP,mRNP