2. زیست شناسی سلولی و مولکولی (Cellular and Molecular Biology)
بخش مهندسی بیوتکنولوژی
عنوان درس:
زیست شناسی سلولی و مولکولی (Cellular and Molecular Biology)
تعداد واحد: 2 (نظری)
روش ارزیابی:
15% سمینار، 35% میان ترم و 50% پایان ترم

3. Regulation of Gene Expression
Lecture 3
Regulation of Gene Expression

4. Recently it has become clear that only a small percentage (7%) of disease-associated single nucleotide polymorphisms (SNPs) are located in protein-coding regions, while the remaining 93% are located in gene regulatory regions or in intergenic regions.

6. Level of Regulation of Gene Expression
Chromatin structure
Initiation of transcription
Processing of the transcript
Transport to the cytoplasm
Translation of mRNA
mRNA stability
Protein activity stability.

8. Control of Gene Expression in Bacteria
In bacteria, the genes that encode the enzymes of a metabolic
pathway are usually clustered together on the chromosome
in a functional complex called an operon.

9. Sigma Factors
Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play critical roles in transcription initiation, including the recognition and opening of promoters as well as the initial steps in RNA synthesis

11. The lac operon

12. The trp operon In a repressible operon, such as the tryptophan
(or trp) operon, the repressor is unable to bind to the
operator DNA by itself. Instead

14. Many Bacterial Responses Are Controlled by Two-Component Regulatory Systems

16. Three-dimensional structures of bacterial and eukaryotic RNA polymerases.
This heptapeptide repeat, with a consensus sequence of Tyr-Ser-Pro-Thr-Ser-Pro-Ser, is known as the carboxyl-terminal domain (CTD)

17. Structure of the 5 methylated cap of eukaryotic mRNA
The cap protects an mRNA from enzymatic degradation and assists in its export to the cytoplasm. The cap also is bound by a protein factor required to begin translation
in the cytoplasm

18. Transcription from a particular promoter is controlled by DNA- binding proteins, termed transcription factors, that are equivalent to bacterial repressors and activators.a

19. Regulatory Sequences in Protein-Coding Genes
TATA Box
Initiators
CpG Islands
(5) Y-Y-A1-N-T/A-Y-Y-Y (3)
Most genes of this type contain a CG-rich stretch of 20–50 nucleotides
within ≈100 base pairs upstream of the start-site region.

20. Promoter-Proximal Elements
control regions lying within 100–200 base pairs upstream of the start site.
Enhancers: long-distance transcription-control elements (>200 bp)

22. Activators and Repressors of Transcription
DNase I footprinting
Electrophoretic mobility shift assay
Sequence specific DNA affinity chromatography

23. DNase I footprinting

24. Electrophoretic mobility shift assay

25. Sequence specific DNA affinity chromatography