细胞分子生物学 第11章 基因表达的转录调控

Enhancer: 能增强转录起始的序列； 能增强转录起始的序列； promoter-proximal elements： ： (近端启动子元件 位于起始位点上游 近端启动子元件) 个碱基。 近端启动子元件 位于起始位点上游100-200个碱基。某些情况下，具有细胞类型特异性， 个碱基 某些情况下，具有细胞类型特异性， 只在特殊的分化细胞类型中起作用
11.7 Regulated Elongation and Termination of Transcription
11.8 Other Eukaryotic Transcription Systems • other two eukaryotic nuclear RNA polymerases, Pol I and Pol III, and by the distinct polymerases that transcribe mitochondrial and chloroplast DNA. • The process of transcription initiation by Pol I and Pol III is similar to that by Pol II but requires different general transcription factors, is directed by different promoter elements, and does not require ATP hydrolysis.
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General Transcription Factors (TF) Position RNA Polymerases II at Start Sites and Assist in Initiation Sequential Assembly of Proteins Forms the Pol II Transcription Preinitiation Complex TATA box–binding protein (TBP) carboxyl-terminal domain (CTD): Tyr-Ser-Pro-Thr-Ser-Pro-Ser
Like activators, most eukaryotic repressors are modular proteins that have two functional domains: a DNA-binding domain and a repression domain
11.4 Transcription Initiation by RNA Polymerase II
11.1 Overview of Eukaryotic Gene Control and RNA Polymerases
• The nuclei of all eukaryotic cells contain three different RNA polymeras, designated I, II, and III. RNA polymerase I, located in the nucleolus, transcribes genes encoding precursor rRNA (pre-rRNA). RNA polymerase II transcribes all protein-coding genes; RNA polymerase III transcribes genes encoding tRNAs.
11.5 Molecular Mechanisms of Transcription Activation and Repression
• 激活子和抑制子通过与 DNA的特殊部位结合来调 节蛋白基因的表达，主要 有2种机制： 种 • 1 激活子和抑制子与其他 蛋白协作调节染色质的结 调节染色质的结 构，从而影响一般转录因 子与启动子的结合； • 2 激活子和抑制子与多蛋 白复合物（转录复合物的 调节子）相互作用，这一 调节 调节子与Pol II结合调节 转录起始复合物的作用； 转录起始复合物
11 TRANSCRIPTIONAL CONTROL OF GENE EXPRESSION
11.1 Overview of Eukaryotic Gene Control and RNA Polymerases 11.2 Regulatory Sequences in Protein-Coding Genes 11.3 Activators and Repressors of Transcription 11.4 Transcription Initiation by RNA Polymerase II 11.5 Molecular Mechanisms of Transcription Activation and Repression 11.6 Regulation of Transcription-Factor Activity 11.7 Regulated Elongation and Termination of Transcription 11.8 Other Eukaryotic Transcrand Repressors of Transcription
• Activators Are Modular Proteins Composed of Distinct Functional Domains • Repressors Are the Functional Converse of Activators
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11.2 Regulatory Sequences in Protein-Coding Genes
General pattern of control elements that regulate gene expression in multicellular eukaryotes and yeast
11.6 Regulation of Transcription-Factor Activity
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Hormone Binding to a Nuclear Receptor Regulates Its Activity as a Transcription Factor All Nuclear Receptors Share a Common Domain Structure