Slide 1

• Topic: Molecular Basis of Inheritance - Promoter of protein-coding region DNA
• Introduction to the topic

Slide 2

• DNA: A brief overview
  • Deoxyribonucleic acid
  • Double helix structure
  • Composed of nucleotides

Slide 3

• Protein-coding regions
  • Genes contain instructions for making proteins
  • Exons: coding regions
  • Introns: non-coding regions

Slide 4

• Promoter region
  • Located upstream of protein-coding regions
  • Plays a crucial role in gene regulation
  • Initiates the transcription process

Slide 5

• Structure of the promoter region
  • Consists of DNA sequences
  • Contains specific motifs and binding sites
  • Interacts with transcription factors

Slide 6

• Transcription factors
  • Proteins that bind to the promoter region
  • Regulate gene expression
  • Can activate or repress transcription

Slide 7

• Types of promoter elements
  • TATA box: Conserved DNA sequence
  • CAAT box: Enhances transcription
  • GC box: Binding site for specific transcription factors

Slide 8

• Transcription initiation complex formation
  • Assembly of RNA polymerase and transcription factors
  • Binding of transcription factors to specific elements
  • Initiation of transcription

Slide 9

• Role of promoter in gene regulation
  • Determines when and how much a gene is expressed
  • Interactions with transcription factors control gene activity
  • Essential for proper cell development and response to stimuli

Slide 10

• Examples of promoter variations
  • Promoter strength can vary
  • Mutations can affect promoter function
  • Promoter differences contribute to genetic diversity

Slide 11

• Regulation of gene expression through promoter elements
  • TATA box: Recognized by TATA-binding protein (TBP)
  • CAAT box: Binds to CCAAT-binding proteins
  • GC box: Interacts with Sp1 transcription factors

Slide 12

• TATA box:
  • Located around -25 to -30 base pairs upstream of the transcription start site
  • Helps in positioning RNA polymerase II at the start site
  • Acts as a nucleosome-free region to allow access for transcription factors

Slide 13

• CAAT box:
  • Found around -70 to -80 base pairs upstream of the transcription start site
  • Enhances the efficiency of transcription initiation
  • Provides stability to the pre-initiation complex

Slide 14

• GC box:
  • Situated around -90 to -100 base pairs upstream of the transcription start site
  • Contains repeats of the sequence GGGCGG or a variation of it
  • Acts as a binding site for specific transcription factors like Sp1

Slide 15

• Transcription start site:
  • Point where RNA polymerase starts synthesizing RNA
  • Designated as +1 nucleotide
  • Position relative to the promoter elements varies among genes

Slide 16

• Regulation through transcription factors
  • Different combinations of transcription factors lead to gene-specific expression
  • Binding or release of transcription factors determines gene activation or repression

Slide 17

• Enhancers:
  • Regions of DNA that can enhance or repress gene expression
  • Located upstream, downstream, or within the gene or even at long distances
  • Interact with promoter elements through DNA looping

Slide 18

• DNA looping:
  • Brings distant enhancers and promoter regions close together
  • Allows for transcriptional regulation over long distances
  • Mediated by proteins that bind to both the enhancer and promoter

Slide 19

• Enhancer-promoter interaction:
  • Involves the formation of a protein complex
  • Enhancer binding proteins recruit activators or repressors to the promoter
  • Activators enhance transcription, while repressors inhibit or reduce it

Slide 20

• Recap:
  • Promoter elements play a vital role in gene regulation
  • TATA box, CAAT box, and GC box serve as binding sites for transcription factors
  • Transcription factors and enhancers control gene expression
  • DNA looping brings enhancers and promoters closer together for regulation

Slide 21

• Examples of gene regulation by promoters
  • In lactose metabolism, the lac operon relies on a promoter to initiate gene expression
  • The promoter region determines when and how much lactose-digesting enzymes are produced in response to lactose availability

Slide 22

• Regulatory sequences in eukaryotes
  • Eukaryotic genes possess complex regulatory elements in their promoter regions
  • Enhancers, silencers, and insulators contribute to gene regulation
  • Binding of transcription factors to these elements influences gene expression

Slide 23

• Control of gene expression by promoter methylation
  • DNA methylation modifies the promoter region to inhibit gene expression
  • Methyl groups are added to cytosine residues in CpG islands
  • Methylation can prevent the binding of transcription factors and RNA polymerase

Slide 24

• Epigenetic regulation of promoters
  • Epigenetic modifications, such as DNA methylation or histone modification, can regulate promoter activity
  • Alterations in these modifications can lead to abnormal gene expression patterns and diseases

Slide 25

• Promoter regions and genetic disorders
  • Mutations or variations in promoter regions can disrupt normal gene regulation and lead to genetic disorders
  • For example, mutations in the FIX gene promoter cause hemophilia B

Slide 26

• Promoter engineering and synthetic biology
  • Scientists can artificially engineer promoters to control gene expression in various applications
  • Synthetic promoters can be designed with specific properties to meet research or industrial needs

Slide 27

• Promoter analysis techniques
  • Various techniques are used to study promoter regions and their functions
  • DNA footprinting, electrophoretic mobility shift assay (EMSA), and reporter gene assays provide insights into promoter activity and regulation

Slide 28

• Future directions in promoter research
  • Continued exploration of promoter elements and their interactions with transcription factors
  • Advancements in genome editing techniques for precise modification of promoter sequences
  • Understanding the impact of promoter variations on gene expression and disease susceptibility

Slide 29

• Summary
  • Promoter regions are essential for gene regulation and initiation of transcription
  • They contain specific elements that interact with transcription factors
  • Enhancers and other regulatory sequences influence promoter activity
  • Promoter mutations or modifications can lead to genetic disorders
  • Promoter engineering and analysis techniques aid in understanding and manipulating gene expression

Slide 30

• Questions (interactive slide)
  • What are the three types of promoter elements typically found in eukaryotic genes?
  • How does DNA looping contribute to gene regulation?
  • Describe the process of transcription initiation complex formation.
  • Can promoter variations affect gene expression? Give an example.
  • How are synthetic promoters used in synthetic biology applications?