《分子生物学》课程教学课件（PPT讲稿）Chapter 7 The Control of Gene Expression

Molecular Biology course chapter 7 The Control of Gene Expression gene regulatory sequences spacer DNA general transcription factors gene regulatory TATA box upstream stert of promote transcription

Chapter 7 The Control of Gene Expression •Molecular Biology Course

The revised central dogma The structure of DNA 因组的保持 DNA Replication ranscription RNA Translation 基因组的表达 Gene regulation Protein 201

2025/5/15 2 The revised central dogma Gene regulation 基 因 组 的 保 持 基 因 组 的 表 达 The structure of DNA

Outline: Section 1 A brief introduction of gene regulation Section 2 Control of gene expression in Prokaryotes Section 3 Control of gene expression in Eukaryotes 2025/5/15 3

2025/5/15 3 Section 1 A brief introduction of gene regulation Section 2 Control of gene expression in Prokaryotes Section 3 Control of gene expression in Eukaryotes Outline:

Key points: Gene expression,activator,repressor,positive gene regulation,negative gene regulation,signal integration,combinational Control,cis-acting element,.trans-acting factor(基因表达、激活蛋白、 阻遏蛋白、正调控与负调控、信号整合、组合控制、 顺式作用元件、反式作用因子等概念；) Positive and negative control of lac operon; Control mechanism of trp operon; Characteristics and levels of eukaryotic gene regulation,types of DNA binding domains of trans-acting factors(真核基因表达调控特点、层次 等，反式作用因子DNA结合结构域类型。) 2025/5/15

2025/5/15 4 Key points: ◼ Gene expression, activator, repressor, positive gene regulation, negative gene regulation, signal integration, combinational Control, cis-acting element, trans-acting factor (基因表达、激活蛋白、 阻遏蛋白、正调控与负调控、信号整合、组合控制、 顺式作用元件、反式作用因子等概念；) ◼ Positive and negative control of lac operon; ◼ Control mechanism of trp operon; ◼ Characteristics and levels of eukaryotic gene regulation, types of DNA binding domains of trans-acting factors (真核基因表达调控特点、层次 等，反式作用因子DNA结合结构域类型。)

Section 1 A brief introduction of gene regulation 2025/5/15 5

2025/5/15 5 Section 1 A brief introduction of gene regulation

Expression of many genes in cells are regulated Housekeeping genes（管家基因) expressed constitutively,essential for basic processes involving in cell replication and growth. Inducible genes(可诱导基因)： expressed only when they are activated by inducers or cellular factors. 202575/15 66

2025/5/15 6 6 Housekeeping genes（管家基因）: expressed constitutively, essential for basic processes involving in cell replication and growth. Inducible genes（可诱导基因）: expressed only when they are activated by inducers or cellular factors. Expression of many genes in cells are regulated

1-1 Cell proteins are divided into two categories: ■Constitutive protein(组成型蛋白质)： In cells,many proteins are the necessary enzymes or proteins in the metabolism, the number of these proteins is not almost affected by the environment or metabolic state. Regulated or adaptive protein(调节型 或适应型蛋白质)： The synthesis rate of these proteins is significantly affected by the environment. 2025/5/15 7

2025/5/15 7 Constitutive protein(组成型蛋白质)： 1-1 Cell proteins are divided into two categories: In cells, many proteins are the necessary enzymes or proteins in the metabolism, the number of these proteins is not almost affected by the environment or metabolic state. Regulated or adaptive protein (调节型 或适应型蛋白质)： The synthesis rate of these proteins is significantly affected by the environment

1-2 Gene regulation Gene expression（基因表达)： refers to the whole process in which the genetic information carried by a gene is converted into a discernible phenotype, generally including two stages,transcription and translation. Gene regulation or gene control 因表达调控) refers to a process in which the gene expression is regulated. 2025/5/15 8

2025/5/15 8 Gene expression（基因表达）： 1-2 Gene regulation Gene regulation or gene control（基 因表达调控） refers to a process in which the gene expression is regulated. refers to the whole process in which the genetic information carried by a gene is converted into a discernible phenotype, generally including two stages, transcription and translation

Gene regulation occurs mainly in two levels ■1.transcriptional regulation转录水平上的调控 ■2.post-transcriptional regulation转录后水 平上的调控 processing of RNA transcript mRNA加工成熟水平上的调控 translation of mRNA 翻译水平上的调控 2025/5/15 9

2025/5/15 9 Gene regulation occurs mainly in two levels ◼ 1. transcriptional regulation转录水平上的调控 ◼ 2. post- transcriptional regulation转录后水 平上的调控 processing of RNA transcript mRNA加工成熟水平上的调控 translation of mRNA 翻译水平上的调控

Gene regulation is affected by the following factors(基因调控的指挥系统)： nutritional status（营养状况) ■In prokaryotes. environmental factors（环境因素 hormone level(激素水平) In eukaryotes developmental stage（发育阶段) 2025/5/15 10

2025/5/15 10 Gene regulation is affected by the following factors (基因调控的指挥系统): ◼ In prokaryotes ◼ In eukaryotes nutritional status（营养状况） environmental factors（环境因素） hormone level（激素水平） developmental stage（发育阶段）