Gene Promoters and Gene Regulation in Eukaryotes

Question 1

How many directions do most TATA and TATA-less promoters transcription initiate and proceed in?

Answer 1

One direction.

Question 2

CpG islands (other promoters) initiate in both directions, but proceed in one directly only. True or false?

Answer 2

True. Transcription initiates at any position (not defined) within the island. It is initiated in both direction, but proceeds only in one direction, over the ORF.

Question 3

How is RNA Pol ll loaded on the promoters?

Answer 3

By the general transcription factors.

Question 4

At the transcription start site (TSS), there is a surge of +50 base pair sequences read per kilo base due to ________.

Answer 4

Uni-directional initiation.

Question 5

CpG islands occupy the promoters of about 70% of genes in vertebrates. At what kind of rate are these genes transcribed?

Answer 5

At a low rate.

Question 6

Why are CpG islands easier to transcribe?

Answer 6

Because they are rich in DNA and contain less nucleosomes.

Question 7

Chromatin Immunoprecipitation (ChIP) uses anti-RNA pol II antibodies to show what?

Answer 7

To show the binding of RNA polymerase II to the analyzed DNA: uni-directional and bi-directional transcription is shown. It binds to the DNA to isolate the DNA. Two Lins of evidence indicate bi-directional initiation of transcription at CpG island.

Question 8

Give a brief summary of the assembly of the pre-initiation complex on TATA-containing promoters. (Promoter elements, GTFs, and RNA pol).

Answer 8

1. Promoter elements (like TATA or the Initiator) direct GTFs to bind to DNA.
2. GTFs position the RNA Polymerase II at the Start sites and Assist in Initiation.

Question 9

The formation of pre-initiation complex commences by the association of TFIID to the promoter followed by ____ and ____.

Answer 9

TFIIB and TBIIA

Question 10

After RNA polymerase is recruited to the pre initiation complex, what happens to the CTD?

Answer 10

The non-phosphorylated CTD of RNA pol II established contact with many GTFS

Question 11

After the CTD makes contact with GTFs in the pre initiation complex, which two TFIIs are recruited?

Answer 11

TFIIE and TFIIH

Question 12

TFII__ (A-H) helices activity facilitates the opening of the double helix of DNA? Does this require energy?

Answer 12

H. Yes it requires energy.

Question 13

TFII__ (A-H) kinase activity phosphorylates the CTD to release RNA polymerase from the promoter.

Answer 13

H.

Question 14

Which TFII(__) has dual helicase and kinase activity?

Answer 14

H.

Question 15

Give the four steps of the transition from initiation to elongation.

Answer 15

1. Assembly of the PIC.
2. Initiation.
3. Release Pol II.
4. Pause.

Question 16

After the initial phosphorylation of the CTD by TFIIH kinase what are the two elongation factors that associate with RNA polymerase ll and pause it downstream of the initiation site?

Answer 16

NELF and DSIF