安徽师范大学：《分子生物学》课程教学课件（讲稿）Chapter 6 Regulation of Gene Expression in Eukaryotes 6.3 Transcriptional Regulation

Chapter6Regulation ofGene ExpressioninEukaryotes

Chapter 6 Regulation of Gene Expression in Eukaryotes

【教学目的】本章要求学生掌握真核生物基因表达调控的基本概念和理论，包括真核生物基因表达调控的多个层次顺式作用元件、反式作用因子及其相互关系，以及真核基因不同水平的表达调控机制等。【重点与难点】1.染色质重塑2.顺式作用元件、人反式作用因子及其相互作用机制3.组蛋白密码4.RNA干扰机制【教学方法】讲述式、多媒体教学、EnglishAnimation【课时安排】6-8课时

【教学目的】 本章要求学生掌握真核生物基因表达调控的基本 概念和理论，包括真核生物基因表达调控的多个层次， 顺式作用元件、反式作用因子及其相互关系，以及真核 基因不同水平的表达调控机制等。 【重点与难点】 1. 染色质重塑 2. 顺式作用元件、反式作用因子及其相互作用机制 3. 组蛋白密码 4. RNA干扰机制 【教学方法】 讲述式、多媒体教学、English Animation 【课时安排】 6-8课时

6.1 MultilevelGene Regulation inEukaryotes6.2 Chromatin Remodeling6.3 TranscriptionalRegulation6.4 Post-TranscriptionalRegulation6.5 Translational Regulation6.6 Translational and Post-translational RegulationSummary

6.1 Multilevel Gene Regulation in Eukaryotes 6.2 Chromatin Remodeling 6.3 Transcriptional Regulation 6.4 Post-Transcriptional Regulation 6.5 Translational Regulation 6.6 Translational and Post-translational Regulation Summary

6.3Transcriptional RegulationCis-Acting Element(1) What is cis-acting element?--- DNA sequences close to a genethat are required for gene expression

6.3 Transcriptional Regulation 1. Cis-Acting Element (1) What is cis-acting element? - DNA sequences close to a gene that are required for gene expression

(2)Featuresof Cis-ActingElementscontainshortconsensussequencesnot fixed in location butusually within 2oo bpusually upstreamofthetranscriptionstartsitea singleelementis usuallysufficientforregulationmany ofthemcouldbindspecificproteins

(2) Features of Cis-Acting Elements ➢ contain short consensus sequences ➢ not fixed in location but usually within 200 bp ➢ usually upstream of the transcription start site ➢ a single element is usually sufficient for regulation ➢ many of them could bind specific proteins

ExamplesTATA boxGC boxCAAT boxPromoterEnhancerSilencerInsulator

TATA box GC box CAAT box Promoter Enhancer Silencer Insulator . Examples

(3)TypesCis-acting elements may be dividedinto two types:positve control elements→acivate transcriptionnegaitve control elements→represstranscription

(3) Types Cis-acting elements may be divided into two types:  positve control elements → acivate transcription  negaitve control elements → repress transcription

2. Major Types of Cis-Acting Element(1)Promoter--ln genetics, a promoter is a regionof DNA that facilitates the transcription ofa particular gene.Corepromoterin eukaryote: TATA-box, Initiator (Inr)in prokaryote: -10 region, Inr

2. Major Types of Cis-Acting Element (1) Promoter -In genetics, a promoter is a region of DNA that facilitates the transcription of a particular gene. ❖ Core promoter  in eukaryote: TATA-box, Initiator (Inr)  in prokaryote: -10 region, Inr

Proximal elementsofpromoterin prokaryote: -35 regionCAAT-box, GC-boxin eukaryote:UPE: upstream promoter elementUAS: upstream activating sequence

❖ Proximal elements of promoter  in prokaryote: -35 region  in eukaryote: CAAT-box, GC-box UPE: upstream promoter element UAS: upstream activating sequence

Prokaryoticpromoter3'5'10-501-10-40-20-305'3'-35startregion-10regionTTGACAAACTGTTATAATATATTA(Pribnowbox)Consensussequence