细胞与分子生物学2

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1、ReactiveOxygenSpecies(ROS)SignaltransductionAyingZhangSignalTransduction•“Nomanisanisland”NocelllivesinisolationCellTissueOrganOrganism•Manybiologicalprocessesrequirevariouscellstoworktogetherandtocoordinatetheiractivities.•Tomakethispossible,cellshav

2、etocommunicatewitheachother,whichisaccomplishedbyaprocesscalledcellsignalingtransduction.SignalTransductionCellsignalingaffectsvirtuallyeveryaspectofcellstructureandfunctionCellgrowthCelldivisionResponsetoStressesApoptosis(ProgrammedCelldeath)Extracel

3、lularmessengermoleculestravelingAutocrine(a),paracrine(b),andendocrine(c)typesofintercellularsignalingCellandMolecularBiology7eFigure15.1EliminateDegradeAnoverviewofthemajorsignalingpathwaysbywhichextracellularmessengermoleculescanelicitintracellularr

4、esponses.CellandMolecularBiology7eFigure15.2SignaltransductionThisoverallprocessinwhichinformationcarriedbyextracellularmessengermoleculesistranslatedintochangesthatoccurinsideacellisreferredtoassignaltransduction.ExtracellularMessengersAminoacidsan

5、daminoacidderivatives.Gases,suchasNOandCO.Steroids,whicharederivedfromcholesterol.hormonesEicosanoids,whicharenonpolarmoleculescontaining20carbonsthatarederivedfromafattyacidnamedarachidonicacid.Awidevarietyofpolypeptidesandproteins.Extracellularm

6、essengermoleculestravelingAutocrine(a),paracrine(b),andendocrine(c)typesofintercellularsignalingCellandMolecularBiologyFigure15.1ReceptorsGprotein-coupledreceptors(GPCRs).Receptorprotein-tyrosinekinases(RTKs).Ligand-gatedchannels.Steroidhormonerec

7、eptors.Othertypesofreceptors.Gprotein-coupledreceptors(GPCRs)ThousandsofCellandMolecularBiologyFigure15.5TABLE15.1ExamplesofPhysiologicProcessesMediatedbyGPCRsandHeterotrimericGProteinsStimulusReceptorEffectorPhysiologicresponseEpinephrineβ-Adrenergi

8、creceptorAdenylylcyclaseGlycogenbreakdownSerotoninSerotoninreceptorAdenylylcyclaseBehavioralsensitizationandlearninginAplysiaLightRhodopsincGMPphosphodiesteraseVisualexcitationIgE–antigenMastcellIgEreceptorPhospholipaseCSecretioncomplexesf-Met