TLS Online TPP Program

#Question id: 12186


In 2001, the Nobel Prize in Physiology or Medicine was awarded to three cell cycle scientists. Paul Nurse was recognized for his studies with the fission yeast S. pombe, in particular for the discovery and characterization of the wee1+ gene. What did the characterization of the wee1+ gene tell us about cell cycle control?

#Unit 2. Cellular Organization
  1. The dual-specificity protein kinase Wee1 phosphorylates CDKs on the activatory tyrosine 15.
  2. Yeast cells with a defective wee1+ gene activate S phase CDKs prematurely and hence experience premature entry into DNA replication. 
  3. Fission yeast cells carrying a CDK1 mutation in which the tyrosine 15 residue is replaced by phenylalanine (which is structurally similar to tyrosine but cannot be phosphorylated) show the premature mitotic CDK activation and entry into mitosis.
  4. The dual-specificity protein phosphatase Wee1 dephosphorylates CDKs on the inhibitory tyrosine 15.

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TLS Online TPP Program

#Question id: 4071

#Unit 3. Fundamental Processes

The fact that a specific protein leaves a “footprint” on a DNA molecule is indicative of

a. a lack of interaction between the specific protein and DNA.

b. protection from DNAse by the specific protein.

c. binding of the specific protein to all types of DNA.

d. binding of the specific protein to a specific sequence of DNA.

TLS Online TPP Program

#Question id: 4072

#Unit 3. Fundamental Processes

The C-terminal activation domain of transcriptional activators is capable of

a. binding to DNA. 

b. stimulating transcription.

c. interaction with other transcriptional machinery.

d. functioning in a fusion with a DNA-binding domain from an unrelated transcriptional activator.

TLS Online TPP Program

#Question id: 4073

#Unit 3. Fundamental Processes

The expression of which gene(s) is (are) regulated by promoter proximal pausing?

TLS Online TPP Program

#Question id: 4074

#Unit 3. Fundamental Processes

The promoter sequences of RNA polymerase III-transcribed genes are located

TLS Online TPP Program

#Question id: 4075

#Unit 3. Fundamental Processes

Pre-mRNA molecules

a. exist as free RNA molecules in eukaryotic cells.

b. are associated with an abundant set of nuclear proteins.

c. are mostly located in the cytoplasm.

d. are located in the nucleus.

TLS Online TPP Program

#Question id: 4076

#Unit 3. Fundamental Processes

RNA-binding proteins

a. can be identified by chromatography of UV irradiated nuclear extracts over oligo-dT columns.

b. can be identified by sequence homology to known RNA-binding domains.

c. have a conserved structure as seen by X-ray crystallographic analysis.

d. alter the secondary structure of pre-mRNAs, which decreases interactions with other RNAs or proteins.

e. always remain in the nucleus.