Epigenetics I

Question 1

What is epigenetics?

Answer 1

heritable changes
no change in DNA sequence

Question 2

3 Types of Epigenetics

Answer 2

1) Modify histones (phosphorylate, methylate, acetylate)
2) DNA methylation = repression
3) Non-coding RNAs

Question 3

Histone Modifications

Answer 3

Acetylation (transcription)
Methylation (express/repress)
Sumoylation (silencing)
Phosphorylation (express)
Ubiquination (express/repress)

Question 4

3 Types of Epigenetic Jobs

Answer 4

1) Writers – add marks (HATs)
2) Readers – recognize marks (bromodomains)
3) Erasers – remove marks (HDACs)

Question 5

Histone Acetylation

Answer 5

Transfer acetyl to histones = unwind DNA
- HAT A – only in nucleus
- HAT B – active in cytoplasm + modify new histones
- recruited by TF

Question 6

Histone Deacetylation

Answer 6

Remove acetyl from histones = wind DNA
- Class I (1-3, 8) – only in nucleus
- Class II (4-7, 9, 10) – nucleus and cytoplasm
- recruited by TF

Question 7

HDACs in Cancer

Answer 7

Roadblocks to Overcome
- poor bioavailability, solid tumours, off-target toxicity