1、基因表达和调控(共157张精选PPT)An example of genetic control of metabolism The products of gene expression can be RNA or proteinBasic concept of transcriptionA transcription unit：PROKARYOTES AND THEIR VIRUS调节基因调节基因操纵子操纵子Lac 阻遏物阻遏物半乳糖苷酶半乳糖苷酶半乳糖苷半乳糖苷透性酶透性酶半乳糖苷半乳糖苷乙酰基转移酶乙酰基转移酶E.Coli 诱导型诱导型Lac操纵子结构模型操纵子结构模型基因基因 长度长
2、度PI:i基因启动子基因启动子 gene i：调节基因调节基因 P：结构结构基因启动子基因启动子 gene Z,Y,A：结构：结构基因基因 O：操纵单元操纵单元 Lac 操纵子基因的组成型表达：操纵子基因的组成型表达：外源诱导物不存在时，外源诱导物不存在时，功能基因仍表达功能基因仍表达THE CENTRAL DOGMAThe difference of gene expression between prokaryotes and eukaryotes Basic concept of transcriptionBasic concept of transcriptionBasic conce
3、pt of transcriptionBasic 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 monophosphate residues are inserted into
4、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，具有终止转录的作用。Bacteriophage Lambda:Lysogeny
5、or LysisBasic concept of transcriptionBasic concept of transcriptionRNA SYNTHESISBasic concept of transcriptionBasic concept of transcriptionRNA initiation in E.coliA:T rich region Initiate unwindingRNA polymerase binding siteTranscription begins Basic concept of transcriptionPROMOTEROF BACTERIABasi
6、c concept of transcriptionBasic concept of transcriptionRNA elongation in E.coliBasic concept of transcriptionBasic concept of transcriptionBasic concept of transcriptionA Rho-independent transcription terminatorBasic concept of transcriptionTranscription in Eukaryotes:Basic concept of transcription
7、Basic concept of transcriptionBasic concept of transcriptionStructure of a promoter recognized by RNA polymerase IIBasic concept of transcriptionBasic concept of transcriptionInitiation of transcription by RNA polymerase IIBasic concept of transcriptionBasic concept of transcriptionBasic concept of
8、transcriptionRNA elongation and the addition of 5-capBasic concept of transcriptionRNA termination and the addition of 3-poly(A)tails RNA processing RNA SPLICING RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA processing RNA
9、 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 processingRNA EDITING:Genetic information is altered in the mRNA RNA processing RNA proce
10、ssingEditing of the apolipoprotein-B mRNA in the intestines of mammals RNA processingEditing of the mitochondrial cytochrome b pre-mRNA RNA processingThe two-step mechanism by which uridine monophosphate residues are inserted into pre-mRNA molecules during editing in mitochondria of trypanosomes RNA
11、 processing RNA processing RNA processing 2.RNA processing 3.RNA stability5 levels of regulation:TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION TRANSLATION
12、PROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSBacteriophage lambdaTwo intracellular states：Lytic growthlysogenyPROKARYOTES AND THEIR VIRUSRepression of the lambda lytic genes in lysogenic PROKARYOTES AND THEIR VIRUSThe lambda repressor dimer contacts its binding sites in lambda operator regi
13、on(OL and OR)PROKARYOTES AND THEIR VIRUSAutogenous regulation of phage lambda repressor synthesisPROKARYOTES AND THEIR VIRUSGenes and recognition sites invovled in the lambda lytic regulatory casadeGenes cro,N and Q encode regulatory proteins required for lytic development PROKARYOTES AND THEIR VIRU
14、SFunctions of the cro gene productPROKARYOTES AND THEIR VIRUSN protein functions as an antiterminator of transcriptionPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSRegulatory element involved in setting the lambda genetic switch to lytic or to lysogeny growthPROKARYOTES AND THEIR VIRUSThe la
15、mbda CII-CIII-PRE regulatory circuitPROKARYOTES AND THEIR VIRUSSummary of the lambda regulatory elementsPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSThe coordination between ribosomal protein synthesis and ribosomal RNA synthesis occurs at the level of translation
16、 PROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSPROKARYOTES AND THEIR VIRUSFeedback inhibition or end-product inhibitioneukaryotesOrgnanization and temporally specific expression of human and globin geneseukaryotesThe stages at which eukaryotic gene expression can be regulated:TranscriptionPr
17、ocessingTranslationeukaryoteseukaryoteseukaryoteseukaryoteseukaryoteseukaryoteseukaryotesEnvironment factors induce transcriptional activity:temperatureeukaryoteseukaryotesBiological factors induce transcriptional activity1:steroid hormoneseukaryotesBiological factors induce transcriptional activity
18、2:peptide hormoneeukaryotesDNA sequences involved in the control of transcription:enhancereukaryoteseukaryotesStructure of the enhancer of SV40融合基因构建：将细菌编码融合基因构建：将细菌编码半乳糖苷酶的半乳糖苷酶的lacZ基因插入果蝇基因插入果蝇P因子，因子，lacZ基因受基因受P因子启动子调控因子启动子调控P/lacZ 融融合基因合基因品系三 所有组织均显为蓝色PROKARYOTES AND THEIR VIRUS停止转录合成底物的结构基因。Auto
19、genous regulation of phage lambda repressor synthesisthe length of the poly(A)tail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。融合基因构建：将细菌编码半乳糖苷酶的lacZ基因插入果蝇P因子，lacZ基因受P因子启动子调控终止子结构特征：基因3端的具有反向重复特殊序列，具有终止转录的作用。The lambda CII-CIII-PRE regulatory circuit将融合基因（fusion gene）与催化P因子转座的酶共同显微注射至果蝇胚胎细胞中Initiation of transcription by RNA polymerase IIRNA processingP/lacZ融合基因在果蝇染色体上受调控序 列增强子(enhancer)的调控。反转录：依赖于RNA的DNA多聚酶原核与真核生物基因转录RNA processing只在眼中只在眼中表达表达只在肠只在肠 中表达中表达 广泛表达广泛表达眼特异增强子眼特异增强子肠特异增强子肠特异增强子广泛增强子广泛增强子
