基因表达和调控(共157张精选PPT)

1、基因表达和调控(共157张精选PPT)基因表达和调控(共157张精选PPT)An example of genetic control of metabolism An example of genetic control The products of gene expression can be RNA or proteinThe products of gene expressioBasic concept of transcriptionA transcription unit：Basic concept of transcription基因和表达与调控调节元件转录调控翻译调控基因和表

2、达与调控调节元件The Lactose Operon in PROKARYOTES AND THEIR VIRUS调节基因操纵子Lac 阻遏物半乳糖苷酶半乳糖苷透性酶半乳糖苷乙酰基转移酶E.Coli 诱导型Lac操纵子结构模型基因 长度PI: i基因启动子 gene i：调节基因 P： 结构基因启动子 gene Z,Y,A：结构基因 O： 操纵单元 The Lactose Operon in PROKARYO诱导系统负调控乳糖操纵子在乳糖存在下，乳糖作为诱导物， 与调节基因产生的阻遏物结合，改变了阻遏物结构，不能再结合到操作基因上，使得RNA多聚酶能够与启动子结合，启动。转录了分解乳糖的三个结

3、构基因。当乳糖分解完以后，调节基因产生的阻遏物结合到操作基因上，使得RNA多聚酶不能够与启动子结合，启动。停止转录分解乳糖的结构基因。诱导系统负调控乳糖操纵子在乳糖存在下，乳糖作为诱导物， 诱导系统负调控 调节基因产物结合到操作基因基因上，启动结构基因不能转录。在底物存在下，底物作为诱导物， 与调节基因产生的阻遏物结合，改变了阻遏物结构，不能再结合到操纵基因上，使得RNA多聚酶能够与启动子结合，启动。转录了分解底物的结构基因。当底物分解完以后，调节基因产生的阻遏物结合到操纵基因上，使得RNA多聚酶不能够与启动子结合，启动。停止转录分解底物的结构基因。诱导系统负调控 调节基因产物结合到操作基因基

4、因上，启诱导系统正调控 调节基因产物结合到操作基因基因上，启动结构基因转录。在底物存在下，底物作为诱导物， 与调节基因产生的活化物结合，改变了活化物结构，使得复合物能够结合到操纵基因上，RNA多聚酶能够与启动子结合，启动。转录了分解底物的结构基因。调节基因的产物在没有底物存在下，不能与结合到操纵基因上，RNA多聚酶不能够与启动子结合，启动。停止转录分解底物的结构基因。诱导系统正调控 调节基因产物结合到操作基因基因上，启动基因表达和调控(共157张精选PPT)阻遏系统负调控 调节基因产物结合到操作基因基因上，启动结构基因不能转录。在底物存在下，调节基因产生的阻遏物不能与操纵基因结合，使得RNA多

5、聚酶能够与启动子结合，启动。转录了合成底物的结构基因。当底物合成以后，调节基因产生的阻遏物与底物的复合物结合到操纵基因上，使得RNA多聚酶不能够与启动子结合，启动。停止转录合成底物的结构基因。阻遏系统负调控 调节基因产物结合到操作基因基因上，启阻遏系统正调控 调节基因产物结合到操作基因基因上，启动结构基因能转录。调节基因产生的活化物与操纵基因结合，使得RNA多聚酶能够与启动子结合，启动。转录了合成底物的结构基因。当底物合成以后，调节基因产生的活化物与底物的复合物不能结合到操纵基因上，使得RNA多聚酶不能够与启动子结合，启动。停止转录合成底物的结构基因。阻遏系统正调控 调节基因产物结合到操作基因

6、基因上，启基因表达和调控(共157张精选PPT)诱导和阻遏系统主要区别调控类型 有底物 无底物诱导系统 阻遏系统 诱导和阻遏系统主要区别正负调控区别调控类型 有阻遏物 无阻遏物负调控 正调控 _正负调控区别调控类型 有阻遏物 Lac 操纵子基因的组成型表达： 外源诱导物不存在时， 功能基因仍表达Lac 操纵子基因的组成型表达： 复制与转录DNA复制：DNA多聚酶转录：依赖于的RNA多聚酶反转录：依赖于RNA的DNA多聚酶复制与转录DNA复制：DNA多聚酶THE CENTRAL DOGMATHE CENTRAL DOGMA基因表达过程DNASnRNA; _tRNA _rRNA _mRNA基因表达

7、过程DNASnRNA;THE PROCESS OF GENE EXPRESSIONTHE PROCESS OF GENE EXPRESSION原核与真核生物基因转录原核 mRNA真核 pre-mRNA -mRNA原核与真核生物基因转录原核 mRNAThe difference of gene expression between prokaryotes and eukaryotes The difference of gene express基因表达和调控(共157张精选PPT)基因表达和调控(共157张精选PPT)调节水平转录m加工翻译翻译后加工调节水平转录Basic concept of

8、transcriptionBasic concept of transcription转录模版 转录时，一般以一条链为模版链，但是也有一些基因以另一条链为模版。转录模版 转录时，一般以一条链为模版链，但是也有一Basic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcription反义RNA：一种由两条互补链转

9、录成的两条完全互补的RNA链，结果形成复合体，不能翻译出蛋白多肽。反义RNA：一种由两条互补链转录成的两条完全互补的RNBasic concept of transcriptionBasic concept of transcriptionRNA processingTrans-acting，反式作用转录了分解底物的结构基因。The difference of gene expression between prokaryotes and eukaryotesRNA processingRNA processingThe two-step mechanism by which uridine

10、monophosphate residues are inserted into pre-mRNA molecules during editing in mitochondria of trypanosomes调节基因产物结合到操作基因基因上，启动结构基因不能转录。PROKARYOTES AND THEIR VIRUSGenes and recognition sites invovled in the lambda lytic regulatory casade原核与真核生物基因转录TRANSLATION可以相隔数千个碱基对远距离发生调控作用。终止子结构特征：基因3端的具有反向重复特殊序列

11、，具有终止转录的作用。Bacteriophage Lambda:Lysogeny or LysisRNA processingBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionRNA SYNTHESISBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionRNA多聚酶与启动子解旋与启始10区：TATA box（Pribnow box），核心酶

12、结合区。35区：sigma因子结合区。RNA多聚酶与启动子解旋与启始Basic concept of transcriptionRNA initiation in E. coliA:T rich region Initiate unwindingRNA polymerase binding siteTranscription begins Basic concept of transcriptionBasic concept of transcriptionPROMOTEROF BACTERIABasic concept of transcriptionBasic concept of tra

13、nscriptionBasic concept of transcription解旋酶和恢复螺旋的酶解旋酶打开部分DNA双螺旋，使得RNA转录。恢复螺旋的酶在转录结束后，恢复原来DNA的双螺旋状。解旋酶和恢复螺旋的酶Basic concept of transcriptionRNA elongation in E. coliBasic concept of transcriptionTermination of RNAA Rho-dependent transcription terminator: result in termination only in the presence of p

14、rotein rho()A Rho-independent transcription terminator: result in termination without the involvement of protein rho()Basic concept of transcriptionTermination of RNAA Rho-depend转录终止 终止：RNA转录停止在终止信号上，RNA释放。Rho因子：在转录中起到终止转录的作用的辅助蛋白。 依赖Rho因子的终止子是弱终止子，不依赖Rho因子的终止子是强终止子。终止子结构特征：基因3端的具有反向重复特殊序列，具有终止转录的作用

15、。转录终止 终止：RNA转录停止在终止信号上，RNA释放Basic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionA Rho-independent transcription terminatorBasic concept of transcriptionBasic concept of transcriptionTranscription in Eukaryotes:Basic concept of transcriptionBasic concept of trans

16、criptionBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionStructure of a promoter recognized by RNA polymerase IIBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcription参与RNA多聚酶作用的因子TFIID:结合到TATA上

17、TFIIA：结合到D上TFIIB：结合复合物TFIIF：与RNA II多聚酶结合，参与解旋 TFIIE：结合复合物参与RNA多聚酶作用的因子TFIID:结合到TATA上Basic concept of transcriptionInitiation of transcription by RNA polymerase IIBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionBasic concept of t

18、ranscriptionRNA加工5加甲基MG3加多聚RNA加工5加甲基MGBasic concept of transcriptionRNA elongation and the addition of 5- capBasic concept of transcriptionBasic concept of transcriptionRNA termination and the addition of 3- poly(A) tailsBasic concept of transcription RNA processing RNA SPLICING RNA processing RNA S

19、PLICIN RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA proc

20、essing RNA processing RNA processing基因表达和调控(共157张精选PPT) RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA

21、processing RNA processing alternative splicing RNA processing alternative splicing RNA pr RNA processing RNA processing RNA processing RNA processing RNA processingRNA EDITING:Genetic information is altered in the mRNA RNA processingRNA EDITING:RNA editing processes alter the information content of

22、gene transcripts in two ways:1.changing the structures of individual bases2.inserting or deleting uridine monophosphate residues RNA processingRNA editing processes alter th RNA processingEditing of the apolipoprotein-B mRNA in the intestines of mammals RNA processingEditing of the RNA processingEdi

23、ting of the mitochondrial cytochrome b pre-mRNA RNA processingEditing of the RNA processingThe two-step mechanism by which uridine monophosphate residues are inserted into pre-mRNA molecules during editing in mitochondria of trypanosomes RNA processingThe two-step metRNA processing RNA processingtRN

24、A processing RNA processing RNA processing RNA processing RNA processing RNA processing 2.RNA processing 3.RNA stability5 levels of regulation: 2.RNA processing 3.RNA stabi TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLA

25、TION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATIONBacteriophage Lambda

26、:Lysogeny or LysisPROKARYOTES AND THEIR VIRUSBacteriophage Lambda:LysogenPROKARYOTES AND THEIR VIRUSBacteriophage lambdaTwo intracellular states：Lytic growthlysogenyPROKARYOTES AND THEIR VIRUSBacThe determination of whether lambda enters the lytic or the lysogenic pathway: 1.the lytic regulatory cas

27、cade or 2.the autogenously maintained repression circuit of lysogenyQ: How the genetic switch of these two regulatory networks takes place? The determination of whether lPROKARYOTES AND THEIR VIRUSRepression of the lambda lytic genes in lysogenic PROKARYOTES AND THEIR VIRUSRepPROKARYOTES AND THEIR V

28、IRUSThe lambda repressor dimer contacts its binding sites in lambda operator region(OL and OR) PROKARYOTES AND THEIR VIRUSThePROKARYOTES AND THEIR VIRUSAutogenous regulation of phage lambda repressor synthesisPROKARYOTES AND THEIR VIRUSAutPROKARYOTES AND THEIR VIRUSGenes and recognition sites invovl

29、ed in the lambda lytic regulatory casadeGenes cro, N and Q encode regulatory proteins required for lytic development PROKARYOTES AND THEIR VIRUSGenPROKARYOTES AND THEIR VIRUSFunctions of the cro gene productPROKARYOTES AND THEIR VIRUSFunPROKARYOTES AND THEIR VIRUSN protein functions as an antitermin

30、ator of transcriptionPROKARYOTES AND THEIR VIRUSN pPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSRegulatory element involved in setting the lambda genetic switch to lytic or to lysogeny growthPROKARYOTES AND THEIR VIRUSRegPROKARYOTES AND THEIR VIRUSThe lambda CII-C

31、III-PRE regulatory circuitPROKARYOTES AND THEIR VIRUSThePROKARYOTES AND THEIR VIRUSSummary of the lambda regulatory elementsPROKARYOTES AND THEIR VIRUSSumPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSTranslational control of gene expression The regulation at the level of translation is just

32、fine-tuningIn prokaryotes, transcription, translation and mRNA degradation are coupledThe same transcript produces different amounts of gene product: unequal efficiencies of translational initiation altered efficiencies of ribosome movement differential rates of degradationPROKARYOTES AND THEIR VIRU

33、STranslational control of gene PROKARYOTES AND THEIR VIRUSThe coordination between ribosomal protein synthesis and ribosomal RNA synthesis occurs at the level of translation PROKARYOTES AND THEIR VIRUSThePROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSPROKARYOTES AND

34、 THEIR VIRUSPost-translation regulatoryPROKARYOTES AND THEIR VIRUSFeedback inhibition or end-product inhibitionPost-translation regulatoryPRORegulation of Eukaryotic gene expression Spatial regulation tissue-specific gene expressionTemporal regulation temporal specificity, different genes are expres

35、sed at different times, in response to biological signals or environment stimuli eukaryotesRegulation of Eukaryotic gene Orgnanization and temporally specific expression of human and globin geneseukaryotesOrgnanization and temporally sThe stages at which eukaryotic gene expression can be regulated:T

36、ranscriptionProcessingTranslationeukaryotesThe stages at which eukaryoticRNA processing is typical in eukaryotesPhysical separation of the events of gene expression make it possible for regulation to occur in different places eukaryotesRNA processing is typical in eAlternate splicing of RNAeukaryote

37、sAlternate splicing of RNAeukareukaryoteseukaryoteseukaryoteseukaryotesCytoplasmic control of mRNA stability the length of the poly(A) tail the structure of the 3UTR the metabolic state of the cell eukaryotesCytoplasmic control of mRNA st环境因素诱导的转录调控 由于环境因子的改变，使得生物体特定基因的表达受到了相关基因的调控，这种调控形式称为环境因素诱导的转录

38、调控。环境因素诱导的转录调控 温度诱导的转录调控元件热休克基因（HeatShock gene) ：编码热休克蛋白的基因。例如：hsp70 gene热休克转录因子（heat-shock transcription factor,HSTF）：存在于细胞核中一种对温度敏感的多肽因子。热休克反应因子（heat shock response elements,HSEs）：在hsp70 gene上游4090bp，被HSTF识别的DNA序列。温度诱导的转录调控元件热休克基因（HeatShock g温度诱导的转录调控热休克基因（HeatShock gene) 在原核和真核生物中都发现了这类基因，当生物体处于高

39、温时，热休克转录因子（heat-shock transcription factor,HSTF）被激活，结合到热休克反应序列上，促使热休克基因转录，表达的蛋白为HSP70，对细胞在高温下起稳定作用。温度诱导的转录调控热休克基因（HeatShock geneukaryotesEnvironment factors induce transcriptional activity: temperatureeukaryotesEnvironment factors eukaryoteseukaryotes生物因子诱导的转录调控生物体在生物因子诱导下的转录调控。 这类因子的调控一般都需要通过细胞信号传导

40、系统，将信息传递细胞核内的DNA上，诱导了转录进行。 其中有的因子直接进入细胞内参与诱导，有些因子通过细胞跨膜蛋白受体，间接进行诱导。生物因子诱导的转录调控生物体在生物因子诱导下的转录调控。eukaryotesBiological factors induce transcriptional activity1: steroid hormoneseukaryotesBiological factors eukaryotesBiological factors induce transcriptional activity2: peptide hormoneeukaryotesBiologica

41、l factors Three general properties of enhancers they act over relatively large distances their influence on gene expression in independent of orientation their effects are independent of positionThree general properties of en增强子（enhancer） 生物中能够增强基因表达的调控序列。作用特征：可以相隔数千个碱基对远距离发生调控作用。不管正向或反向，均可以发挥调控作用。在结构基因的上游或下游都具有调控的作用。增强子（enhancer） 生物中能够增强基因表达的调eukaryotesDNA sequences involved in the control of transcription: enhancer