Transcriptional control in Eukaryotes Kevin Gaston L1-3

Question 1

What RNAP exists in the Nucleolus of eukaryotes?

Answer 1

RNAP 1

Question 2

What does RNAP1/11/111 transcribe?

Answer 2

RNAPI-rRNA
RNAPII-mRNA and miRNA
RNAPIII-tRNA and 5S RNA

Question 3

Where is the TATA box?

Answer 3

30bps upstream of transcription start point

Question 4

Order of assembly of pre-initiation complex in vivo?

Answer 4

TFIID-multi protein complex-has tata binding protein
One component of TFIID is a histone acetyl transferase
TFIIB and A
RNAP TFIIF
TFIIE and TFIIH

Question 5

What do Srb/Med do?

Answer 5

Mediator complexes

help RNAPII to communicate via protein-protein interactions with TFs

Question 6

How many enhancers do humans have?

Answer 6

70,000 found in non-coding regulatory DNA/junk DNA

Question 7

How long is the Xist long non coding RNA used to inactivate on of the X chromosomes in females?

Answer 7

15kb
Xist binds to the inactive X and this leads to chromatin condensation
Inactive X becomes heavily methylated and condensed

Question 8

What proteins does Xist recruit?

Answer 8

PRC2
H3K27me3 produces transcriptional repression
YY1 tethers Xist to the X chromosome (DNA binding protein)

Question 9

What are the activators and repressors of retinoic acid receptor?

Answer 9

PRD3=co-repressor HDAC activity

CBP=activator HAT activity (only works in presence of retinoic acid)

Question 10

What complex is involved in miRNA in transcription and translation?

Answer 10

Transcription-RITS

Translation-RISC