Gene Transcription

Question 1

Promotor Region

Answer 1

• Bound by General Transcrption factors and RNA pol II
• Defines Transcription Start Site
• Necessary for any transcription to occur

Question 2

Enhancers and Silencers (regulatory elements)

Answer 2

Specific nucleotide sequence
Can be basically anywhere
bind to specific transcription factor
txn factor alters activity of promoters

–> How you get diversity

Question 3

How can issues with Txn factors cause disease

Answer 3

• Irregular /hypo cell development essentially.

- i.e. atrial sepsis defect

Question 4

Lineage determining factors

Answer 4

Bind to regulatory elements’ DNA and drive differentiation of cell type
i.e. GATA 4 in cardiomyocytes

Question 5

3 Main Features of Transcription Factor Architecture

Answer 5

1. DNA Binding Domain
2. Transcription activating domains
   - ->These activate proteins to alter chromatin structure
   - ->Recruits General TXN factors
   - ->Recruit Kinase to activate RNA Pol II
3. Dimerization/protein interaction domains

Question 6

How do TF know where to bind?

Answer 6

Base order recognition and shape readout

–>Amino Acid substitutions affect ability of TXN factors to bind

Question 7

Why do TXN Factors bind to themselves or other TXN Factors

Answer 7

Increase specificity

Question 8

Mechanism of Transcription Activation

Answer 8

1. GATA and TEX5 transcription factors recruit HATS and CRC (Histone acetyltransferase and Cromatin Remodeling Complex) to expose what genes you want expressed.
2. TXN factors bring in General TXN Factors–>RNA POL II
3. PTEF-4 brought in to phosphorylate RNA pol II

Question 9

How do HATs and HDACs work?

Answer 9

Often acetyl group is added to Lysine (+ charge). This repulses DNA, Opening it up for txn.

De-acetylase removes acetyl group which causes DNA to tightly bind to histone,

Question 10

Yomanaka Factors “master regulators”

Answer 10

Oct 3/4, Sox2, Klf4, c-MYC = proteins that can create stem cells

Question 11

PAMPs, PRRS, in immune system?

Answer 11

Pathogen associated molecular paterns and Pathogen Recognition Receptors (TOL).

1. PRRs recognize PAMP on bacteria which activates Nf kappa B
2. Nf Kappa B goes to Nucleus
3. TXN factors for inflammation activated

Question 12

How are Gluccocorticoid anti-inflammatories related to Transcription?

Answer 12

1. Gluccocorticoid receptor in cytoplasm. When signal binds to receptor it can now move into the nucleus.
2. Now can bind to GRE (Glucocorticoid responsive element) in DNA as dimer
3. activates assoc. genes (OR silencing of gene if it is in silencer region)

–> anti inflammatory because gluccocorticoid binds to Nf K b and inhibits it.

Question 13

How to repress TXN:

Answer 13

1. Block binding of General TXN factors
   OR
2. Recruit HDAC

Question 14

Prostate Cancer Risk

Answer 14

Elevated expression of RFX6 gene caused by SNP