13 Control of Eukaryotic Gene Expression

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1、§13TheControlofEukaryotesGeneExpression1WelcometoattendMr.HeGenhe’slecture!1.GeneExpressionisControlledbyRegulatoryProteins(调控蛋白)GeneexpressionisveryoftencontrolledbyExtracellularSignals,whicharecommunicatedtogenesbyregulatoryproteins:Positiveregulatorsoractivators

2、IncreasethetranscriptionNegativeregulatorsorrepressorsDecreaseorEliminatethetranscription2WelcometoattendMr.HeGenhe’slecture!1.Principlesarethesame:signals(信号),activatorsandrepressors(激活蛋白和阻遏蛋白),recruitmentandallostery,cooperativebinding(招募，异构和协同结合)2.Thegeneexpress

3、ionstepssubjectedtoregulationaresimilar,andtheinitiationoftranscriptionisthemostpervasivelyregulatedstep.2.Similarityofregulationbetweeneukaryotesandprokaryotes3WelcometoattendMr.HeGenhe’slecture!Pre-mRNAsplicingaddsanimportantstepforregulation.(mRNA前体的剪接)Theeukary

4、otictranscriptionalmachineryismoreelaboratethanitsbacterialcounterpart.(真核转录机器更复杂)Nucleosomesandtheirmodifiersinfluenceaccesstogenes.(核小体及其修饰体)Manyeukaryoticgeneshavemoreregulatorybindingsitesandarecontrolledbymoreregulatoryproteinsthanarebacterialgenes.(真核基因有更多结合位

5、点)3.Differenceinregulationbetweeneukaryotesandprokaryotes4WelcometoattendMr.HeGenhe’slecture!Alotmoreregulatorbindingssitesinmulticellularorganismsreflectsthemoreextensivesignalintegration5WelcometoattendMr.HeGenhe’slecture!Enhancer(激活元件):agivensitebindsregulatorre

6、sponsibleforactivatingthegene.Alternativeenhancerbindsdifferentgroupsofregulatorsandcontrolexpressionofthesamegeneatdifferenttimesandplacesinresponsibletodifferentsignals.Activationatadistanceismuchmorecommonineukaryotes.Insulators(绝缘子)orboundaryelements(临界元件)arere

7、gulatorysequencesbetweenenhancersandpromoters.Theyblockactivationofalinkedpromoterbyactivatorboundattheenhancer,andthereforeensureactivatorsworkdiscriminately.6WelcometoattendMr.HeGenhe’slecture!一、真核的转录激活蛋白的结构特征Thestructurefeaturesoftheeukaryotictranscriptionactiva

8、torsTopic1:ConservedMechanismsofTranscriptionalRegulationfromYeast(酵母)toMammals(哺乳动物)7WelcometoattendMr.HeGenhe’slecture!Thebasicfeaturesofgenere