最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件

考研資料北京大學(xué)細(xì)胞生物學(xué)第六章基質(zhì)與內(nèi)膜(上)考研資料北京大學(xué)細(xì)胞生物學(xué)第六章基質(zhì)與內(nèi)膜(上)1.TheCompartmentalizationinEukaryoticCellsMembranesdividethecytoplasmofeukaryoticcellsintodistinctcompartments.

Threecategoriesineukaryoticcells:(1)theendomembranesystem:ER,Golgicomplex,Lys.,secretoryvesicles.(2)thecytosol.(3)mitochondria,chloroplasts,peroxisomes,andthenucleus.Membrane-boundstructures(organelles)arefoundinalleukaryoticcells.1.TheCompartmentalizationin2最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件3最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件4最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件5最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件6最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件7最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件8D.AfewapproachestothestudyofcytomembranesInsightsgainedfromautoradiography;Insightsgainedfromthebiochemicalanalysisofsubcellularfractions;Insightsgainedfromthestudyofgeneticmutants;Thedynamicactivitiesofendomembranesystemsarehighlyconserveddespitethestructuraldiversityofdifferentcelltypes.D.Afewapproachestothestu9DeDuve,A.ClaudeandG.Palade,1974NobelPlrizeDeDuve,A.ClaudeandG.Palade102.ThestructureandfunctionsofEndoplasmicReticulum(ER)RoughendoplasmicreticulumandSmoothendoplasmicreticulum

RERhasribosomesonthecytosolicsideofcontinuous,flattenedsacs(cisternae);SERisaninterconnectingnetworkoftubularmembraneelements.2.Thestructureandfunctions11Microsome(100-200nm)rERofpancreaticcellsMicrosomesareheterogeneousmixturesofsimilar-sizedvesicles,formedfrommembranesoftheERandGolgicomplex.Microsomesretainactivityduringpurification,allowingstudiesoffunctionandcomposition.Microsome(100-200nm)rERofpan12A.FunctionsoftherERProteinssynthesizedonribosomesofrERinclude:

secretoryproteins,integralmembraneproteins,solubleproteinsoforganelles.A.FunctionsoftherERProtein13Modificationandprocessingofnewlysynthesizedproteins:glycosylationintherER;N-linked:linkedtotheamidenitrogenofasparagine(ER)O-linked:linkedtothehydroxylgroupserineorthreonineviaGalNac(inGolgi)Theprecursorof14residuesisthesameinplants,animals,andsingle-celledeukaryotesthenremove3glucosesand1mannoseintheERModificationandprocessingof14Qualitycontrolofofnewlysynthesizedproteins---TheroleofN-linkedglycosylationinERproteinfoldingQualitycontrol:ensuringthatmisfoldedproteinsdonotleaveERThelumenofrERcontains:Bipandcalnexin(chaperones):thatrecognizeandbindtounfoldedormisfoldedproteinsandgivethemcorrectconformation;Proteindisulfideisomerase(PDI);GT(glucosyl-transferase,monitoringenenzyme)recognizeunfoldedormisfoldedproteinsandaddsaglucosetotheendofoligo..Qualitycontrolofofnewlys15SynthesisofmembranelipidsMostmembranelipidsaresynthesizedenterlywithintheER.Therearetwoexceptions:sphingomyelinandglycolipids,(beginsinER;completedinGolgi);(2)someoftheuniquelipidsoftheMitandChlmembranes(themself).Themembranesofdifferent0rganelleshavemarkedlydifferentlipidscomposition.Transportbybudding：ER→GC、Ly、PMTransportbyphospholipidexchangeproteins(PEP)：ER→otherorganelles（includingMitandChl）SynthesisofmembranelipidsMo16Theroleofphospholipidtranslocatorsinlipidbilayersynthesisphospholipidtranslocators=Scramblase(ABCtransporterFamily)Theroleofphospholipidtrans17B.FunctionsofthesERSynthesisofsteroidsinendocrinecells.Detoxificationoforganiccompoundsinlivercells.Systemofoxygenases---cytochromep450familyReleaseofglucose6-phosphateinlivercells.SequestrationofCa2+.Ca2+-ATPaseB.FunctionsofthesERSynthes183.ThestructureandfunctionsofGolgicomplexA.ThepolarityofGolgicomplex3.Thestructureandfunctions19a)CiscisternaeofGolgicomplex:reducedosmiumtetroxide(OsO4);b)ReactionforenzymemannosidaseII,localizedinthemedial;c)Reactionforenzymenucleosidediphosphatase,localizedinthetranscisternae.RegionaldifferencesinmembranecompositionacrosstheGolgistacka)CiscisternaeofGolgicomp20B.TheFunctionsofGolgicomplexGlycosylationintheGolgicomplexGolgicomplexplaysakeyroleintheassemblyofthecarbohydratecomponentofglycoproteinsandglycolipids.B.TheFunctionsofGolgicomp21ThecorecarbohydrateofN-linkedoligosaccharidesisassembledintherER.ModificationstoN-linkedoligosaccharidesarecompletedintheGolgicomplex.O-linkedoligosaccharidestakesplaceinGolgicomplex.ThecorecarbohydrateofN22StructureoftypicalO-andN-linkedoligosaccharidesCoreRegionAfterR.KornfeldandS.Kornfeld,1985,Annu.Rev.Biochem.

45:631StructureoftypicalO-andN-23Whatisthepurposeofglycosylation?N-linkedglycosylationisprevalentinalleucaryotes,butisabsentfromprocaryotes.Itdon’trequireatemplate.ThereisanimportantdifferencebetweentheconstructionofanoligosaccharideandthesynthesisofDNA,RNA,andprotein.Importantfunctions:

(1)Onemightsuspectthattheyfunctiontoaidfoldingandthetransportprocess;forexample,carbohydrateasamarkerduringproteinfoldinginERandtheuseofcarbohydrate-bindinglectinsinguidingER-to-Golgitransport.(2)Limittheapproachofothermacromoleculestotheproteinsurface,moreresistanttodigestionbyproteases.(3)Regulatoryrolesinsignalingthroughthecell-surfacereceptorNotch,toallowsthesecellstorespondselectivelytoactivatingstimuli.Whatisthepurposeofglycosy24TheGolginetworksareprocessingandsortingstationswhereproteinsaremodified,segregatedandthenshippedindifferentdirections.TheGolginetworksareprocess25Golgicomplexandcell’ssecretionContinual,unregulateddischargeofmaterialfromthecellsThedischargeofproductsstoredincytoplasmicgranules,inresponsetoappropriatestimuli.Golgicomplexandcell’ssecre26VesivulartransportwithintheGolgiapparatus:

Twoviews:cisternalmaturationmodelandvesiculartransportmodelTwopossiblemodelsexplainingtheorganizationoftheGolgicomplexandthetransportfromonecisternatothenext.Vesivulartransportwithinth27十

十

十

C.GolgiBiogenesisStagesofGolgigrowthanddivision.ShownarethinsectionelectronmicrographsofT.gondiiRHtachyzoitesreplicatingbyendodyogenyinHFFcells.CellswereplacedinoneoffourcategoriesaccordingtothenumberandsizeoftheGolgi:a,singleGolgi;b,single,elongatedGolgi;c,twoGolgi;d,Golgi,oftenmorevesiculated,ineachnascentdaughtercell,delineatedbythegrowinginnermembranecomplex(IMC).a,apicoplast;dg,densegranules;er,ER;es,ERexitsitesontheouterflattenedpartofthenuclearenvelope;G,Golgi;m,micronemes;mit,mitochondria;r,rhoptries.Scalebar,0.5mm.十十十C.GolgiBiogenesisStag28StableexpressionofmammalianGolgiproteins.a,b,OverlaidimmunofluorescenceandphaseimagesofGRASP–YFP(a)andNAGTI–YFP(b)instable,transgeniccelllinesofToxoplasmagondii.c–h,ImmunofluorescenceimagesofatransgeniccelllineexpressingbothGRASP–CFP(green)andNAGTI–YFP(red)before(c–e)orafter(f–h)treatmentwith5mg/mlBFAfor10minat37oC.Mergedimagesareshownontheright.AsterisksindicateasecretedformofNAGTI–YFPthataccumulatesintheparasitophorousvacuole.Scalebars,5mm.Stableexpressionofmammalian29Immunoelectronmicroscopyoftransgenicparasites.a–c,CryosectionsofGRASP–YFP(a,c)orNAGTI–YFP(b)transgenicparasites,pretreatedfor2hwith50mg/mlcycloheximide,beforebeingfixedandimmunolabelledforYFPusingpolyclonalantibodiesagainstGFPfollowedbyproteinAcoupledto5-nmgoldparticles.NotethehighdensityoflabellingrestrictedtoGolgimembranes.Inc,GRASP–YFPtransgenicparasitesweretreatedwithBFA(5mg/ml)for30minbeforeimmunolabelling.Notethetubulo-vesicularappearanceoftheGolgicausedbylossofGolgienzymestotheER.d,Quantificationofimagesinaandb.Resultsarepresentedasmean±s.d.goldparticles/um2.Immunoelectronmicroscopyoft30最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件31考研資料北京大學(xué)細(xì)胞生物學(xué)第六章基質(zhì)與內(nèi)膜(上)考研資料北京大學(xué)細(xì)胞生物學(xué)第六章基質(zhì)與內(nèi)膜(上)1.TheCompartmentalizationinEukaryoticCellsMembranesdividethecytoplasmofeukaryoticcellsintodistinctcompartments.

Threecategoriesineukaryoticcells:(1)theendomembranesystem:ER,Golgicomplex,Lys.,secretoryvesicles.(2)thecytosol.(3)mitochondria,chloroplasts,peroxisomes,andthenucleus.Membrane-boundstructures(organelles)arefoundinalleukaryoticcells.1.TheCompartmentalizationin33最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件34最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件35最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件36最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件37最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件38最新考研資料細(xì)胞生物學(xué)六章基質(zhì)與內(nèi)膜(上)課件39D.AfewapproachestothestudyofcytomembranesInsightsgainedfromautoradiography;Insightsgainedfromthebiochemicalanalysisofsubcellularfractions;Insightsgainedfromthestudyofgeneticmutants;Thedynamicactivitiesofendomembranesystemsarehighlyconserveddespitethestructuraldiversityofdifferentcelltypes.D.Afewapproachestothestu40DeDuve,A.ClaudeandG.Palade,1974NobelPlrizeDeDuve,A.ClaudeandG.Palade412.ThestructureandfunctionsofEndoplasmicReticulum(ER)RoughendoplasmicreticulumandSmoothendoplasmicreticulum

RERhasribosomesonthecytosolicsideofcontinuous,flattenedsacs(cisternae);SERisaninterconnectingnetworkoftubularmembraneelements.2.Thestructureandfunctions42Microsome(100-200nm)rERofpancreaticcellsMicrosomesareheterogeneousmixturesofsimilar-sizedvesicles,formedfrommembranesoftheERandGolgicomplex.Microsomesretainactivityduringpurification,allowingstudiesoffunctionandcomposition.Microsome(100-200nm)rERofpan43A.FunctionsoftherERProteinssynthesizedonribosomesofrERinclude:

secretoryproteins,integralmembraneproteins,solubleproteinsoforganelles.A.FunctionsoftherERProtein44Modificationandprocessingofnewlysynthesizedproteins:glycosylationintherER;N-linked:linkedtotheamidenitrogenofasparagine(ER)O-linked:linkedtothehydroxylgroupserineorthreonineviaGalNac(inGolgi)Theprecursorof14residuesisthesameinplants,animals,andsingle-celledeukaryotesthenremove3glucosesand1mannoseintheERModificationandprocessingof45Qualitycontrolofofnewlysynthesizedproteins---TheroleofN-linkedglycosylationinERproteinfoldingQualitycontrol:ensuringthatmisfoldedproteinsdonotleaveERThelumenofrERcontains:Bipandcalnexin(chaperones):thatrecognizeandbindtounfoldedormisfoldedproteinsandgivethemcorrectconformation;Proteindisulfideisomerase(PDI);GT(glucosyl-transferase,monitoringenenzyme)recognizeunfoldedormisfoldedproteinsandaddsaglucosetotheendofoligo..Qualitycontrolofofnewlys46SynthesisofmembranelipidsMostmembranelipidsaresynthesizedenterlywithintheER.Therearetwoexceptions:sphingomyelinandglycolipids,(beginsinER;completedinGolgi);(2)someoftheuniquelipidsoftheMitandChlmembranes(themself).Themembranesofdifferent0rganelleshavemarkedlydifferentlipidscomposition.Transportbybudding：ER→GC、Ly、PMTransportbyphospholipidexchangeproteins(PEP)：ER→otherorganelles（includingMitandChl）SynthesisofmembranelipidsMo47Theroleofphospholipidtranslocatorsinlipidbilayersynthesisphospholipidtranslocators=Scramblase(ABCtransporterFamily)Theroleofphospholipidtrans48B.FunctionsofthesERSynthesisofsteroidsinendocrinecells.Detoxificationoforganiccompoundsinlivercells.Systemofoxygenases---cytochromep450familyReleaseofglucose6-phosphateinlivercells.SequestrationofCa2+.Ca2+-ATPaseB.FunctionsofthesERSynthes493.ThestructureandfunctionsofGolgicomplexA.ThepolarityofGolgicomplex3.Thestructureandfunctions50a)CiscisternaeofGolgicomplex:reducedosmiumtetroxide(OsO4);b)ReactionforenzymemannosidaseII,localizedinthemedial;c)Reactionforenzymenucleosidediphosphatase,localizedinthetranscisternae.RegionaldifferencesinmembranecompositionacrosstheGolgistacka)CiscisternaeofGolgicomp51B.TheFunctionsofGolgicomplexGlycosylationintheGolgicomplexGolgicomplexplaysakeyroleintheassemblyofthecarbohydratecomponentofglycoproteinsandglycolipids.B.TheFunctionsofGolgicomp52ThecorecarbohydrateofN-linkedoligosaccharidesisassembledintherER.ModificationstoN-linkedoligosaccharidesarecompletedintheGolgicomplex.O-linkedoligosaccharidestakesplaceinGolgicomplex.ThecorecarbohydrateofN53StructureoftypicalO-andN-linkedoligosaccharidesCoreRegionAfterR.KornfeldandS.Kornfeld,1985,Annu.Rev.Biochem.

45:631StructureoftypicalO-andN-54Whatisthepurposeofglycosylation?N-linkedglycosylationisprevalentinalleucaryotes,butisabsentfromprocaryotes.Itdon’trequireatemplate.ThereisanimportantdifferencebetweentheconstructionofanoligosaccharideandthesynthesisofDNA,RNA,andprotein.Importantfunctions:

(1)Onemightsuspectthattheyfunctiontoaidfoldingandthetransportprocess;forexample,carbohydrateasamarkerduringproteinfoldinginERandtheuseofcarbohydrate-bindinglectinsinguidingER-to-Golgitransport.(2)Limittheapproachofothermacromoleculestotheproteinsurface,moreresistanttodigestionbyproteases.(3)Regulatoryrolesinsignalingthroughthecell-surfacereceptorNotch,toallowsthesecellstorespondselectivelytoactivatingstimuli.Whatisthepurposeofglycosy55TheGolginetworksareprocessingandsortingstationswhereproteinsaremodified,segregatedandthenshippedindifferentdirections.TheGolginetworksareprocess56Golgicomplexandcell’ssecretionContinual,unregulateddischargeofmaterialfromthecellsThedischargeofproductsstoredincytoplasmicgranules,inresponsetoappropriatestimuli.Golgicomplexandcell’ssecre57VesivulartransportwithintheGolgiapparatus:

Twoviews:cisternalmaturationmodelandvesiculartransportmodelTwopossiblemodelsexplainingtheorganizationoftheGolgicomplexandthetransportfromonecisternatothenext.Vesivulartransportwithinth58十

十

十

C.GolgiBiogenesisStagesofGolgigrowthanddivision.ShownarethinsectionelectronmicrographsofT.gondiiRHtachyzoitesreplicatingbyendodyogenyinHFFcells.CellswereplacedinoneoffourcategoriesaccordingtothenumberandsizeoftheGolgi:a,singleGolgi;b,single,elongatedGolgi;c,twoGolgi;d,Golg