Gene Expression Review Flashcards
Ser-5 phosphorylation of the C-terminal domain (CTD) of RNA Pol II is associated with which phase of the transcription cycle?
Initiation
Which of the following is NOT part of the eukaryotic mRNA processing?
Acetylation of lysines
A mutation in the U2O snoRNA might lead to what?
incorrect methylation of rRNA
a-amantin is the most deadly toxin found in poisonous mushrooms. Upon ingestion and uptake by liver cells, it binds to RNA Pol II and effectively causes cytolysis. Symptoms of a-amanitin poisoning typically occur within days and death follows around 1 week post-ingestion. What is the mechanism of its toxicity?
prevents mRNA production
The 5s rRNA gene is transcribed from a promoter that include which elements?
A and C box
Which protein does Treacle co-localize with?
UBF
Consistent with the above results, you discover that Treacle is involved in eukaryotic transcription by RNA Pol I. Which subcellular compartment is Treacle localized to?
Nucleolus
Transcription of which gene is Treacle likely to participate in?
5.8sRNA
For patient 1, in what region of the TCOF1 gene did the mutation most likely occur?
an exon
For patient 2, in what region of the TCOF1 gene did the mutation most likely occur?
Inr element (+1)
A mutant cell line is able to carry out siRNA processing but is unable to carry out miRNA processing. Which protein complex is most likely defective in this mutant cell line?
Drosha
What is one function of TFIIH?
unwinds DNA duplex in PIC
What is the major difference between Group 1 and Group 2 of RNS Pol II to facilitate promoter escape?
Group 1 involves nucleophilic attack from a 2’OH of a free GTP. Group 2 uses a 2’OH of a nucleotide contained within the intron
Which region is important for pre-initiation complex (PIC) formation?
TATA
Where would a specific transcription factor bind?
enhancer
What would bridge the signal from region A to region B?
Mediator
This gene would be transcribed by what?
RNA Polymerase II
The Rho protein:
functions in termination of some bacterial genes
One way to make chromatin more accessible to transcriptional machinery is to ____.
acetylate histones
You are analyzing eukaryotic cells that have been exposed to radioactive uracil. In most cells the radioactivity is initially localized in the nucleus, then moves to the cytoplasm. However, you observe that in some cells the radioactivity stays in the nucleus and never arrive in the cytoplasm. This is most likely a defect in what?
RNA processing
What is the function is U6 snRNA?
facilitates splicing of mRNA
Transcription from the bacterial trp operon is regulated by attenuation. This type of regulation does NOT occur in eukaryotic because?
Eukaryotic cells have a nucleus
What is the function of TTF1?
functions in the termination of bacterial genes
What is the function of P-TEFb?
phosphorylates Ser-2 of the CTD of RNA Pol II to facilitate productive transcription elongation
Below is the percent guanosine and cytosine content within genomic DNA 10k bp upstream and 20k bp downstream of a known transcription start site (+1) in a eukaryotic gene. What is the most likely mechanism of regulation of this gene?
DNA methylation
(-) glucose
(-) lactose
Is the lactose repressor bound?
Yes
(-) glucose
(+) lactose
Is the lactose repressor bound?
No
(+) glucose
(-) lactose
Is the lactose repressor bound?
Yes
(+) glucose
(+) lactose
Is the lactose repressor bound?
No
(-) glucose
(-) lactose
Is the CAP-cAMP complex bound?
Yes
(-) glucose
(+) lactose
Is the CAP-cAMP complex bound?
Yes
(+) glucose
(-) lactose
Is the CAP-cAMP complex bound?
No
(+) glucose
(+) lactose
Is the CAP-cAMP complex bound?
No
Under what conditions is the Operon ON?
(-) glucose (+) lactose
ID promoter sequence:
NE on both
ID structural sequence:
has IE
ID operator gene:
If mutated stays the same
ID repressor gene:
If mutated changes
Inducible operon
tm present = AE
tm absent = NE
Repressible operon
tm present = NE
tm absent = AE
