S1 Mitchell (8-17)

Question 1

Assays performed on which gene first detected chromation changes upon gene activation?

Answer 1

ß-globin

Question 2

ChIP assays revealed that Nucleosome Free Regions (NFRs) are found where?

Answer 2

At promoter regions

Question 3

Nucleosomes adjacent to NFRs are encriched in what?

Answer 3

Euchromatin markers

Question 4

What are some euchromatin markers?

Answer 4

• AcH3K9
• MeH3K4

Question 5

What is the SAGA complex?

Answer 5

A histone acetyltransferase complex (HAT)

Question 6

Where is SAGA recruited to?

Answer 6

Upstream Activating Sequences (UAS)

Question 7

How is SAGA recruited?

Answer 7

Through interaction with transcriptional activators, eg Gcn4 and Gal4

Question 8

In more general terms, what is SAGA?

Answer 8

A co-activator

Question 9

Once histones are acetylated, they are recognised by proteins with a specific domain. Which domain is this?

Answer 9

The bromodomain

Question 10

Give some examples of proteins with the monoacetylated-histone recognising domain.

Answer 10

• CRMs
• TFIID

Question 11

What is the catalytic component of the SAGA complex?

Answer 11

Gcn5

Question 12

Which histones does Gcn5 directly acetylate, and for which histone is Gcn5 required indirectly for acetylation?

Answer 12

• H2B, H3
• H4

Question 13

Name two CRMs.

Answer 13

1. SWI
2. SNF

Question 14

What does the helicase activity of CRMs cause?

Answer 14

Nucleosome sliding along DNA

Question 15

What do CRMs bind as a control mechanism?

Answer 15

Activation/Repression domains of TFs

Question 16

In general terms, what is the Sin3/Rpd3 HDAC?

Answer 16

A transcriptional co-repressor

Question 17

What does Sin3 do?

Answer 17

Allows interaction with Ume6, a URS binding transcriptional repressor.

Question 18

What does Rpd3 do?

Answer 18

It is the catalytic histone deacetylase subunit.

Question 19

Transcriptionally inactive reguions of DNA are rich in what residues?

Answer 19

m⁵CG

Question 20

Methylation patters are established in the zygote. In which cells are they mainted, and how?

Answer 20

Stably in somatic cells.

Question 21

MeCP2 binds m⁵CG. What does MeCP2 recruit?

Answer 21

Histone deacetylase or histone methyltransferase complexes