Deck 32: Prions

Question 1

All of the following are examples of human diseases caused by prions EXCEPT…..

A)Kuru
B)Creutzfeldt-Jakob disease
C)Fatal familial insomnia
D)Scrapie
E)Gerstmann-Straussler-Scheinker syndrome

Answer 1

D

Question 2

All prion associated diseases are confined to which of the following organ systems of the body?

A)Immune system.
B)Muscular system.
C)Central nervous system.
D)Digestive system.
E)Endocrine system.

Answer 2

C

Question 3

The normal cellular version of the prion protein is a cytosolic copper-binding protein involved in cell signaling.

Answer 3

False

Question 4

Heterozygosity at codon 129 in the prion gene is present in the human population at an unexpectedly high level.Which of the following may explain why?

A)It is associated with resistance to acquired CJD.
B)It is associated with resistance to sproadic CJD.
C)It is associated with resistance to variant CJD.
D)It is associated with resistance to kuru.
E)All of the above are correct.

Question 5

What is the nature of the infectious agent that causes the human disease kuru?

A)A positive-strand RNA virus.
B)A small RNA molecule similar to a viroid.
C)Kuru is only seen as an inherited genetic disease.
D)A single species of protein called a prion.
E)A small DNA molecule that does not code for a protein.

Question 6

The PrP^Sc protein is more resistant to proteases than the PrP^C protein.

Question 7

Which of the following describes the primary difference between the normal PrP^C protein and the disease version of the protein (PrP^Sc).

A)PrP^Sc contains additional octapeptide repeats at the N-terminus.
B)PrP^Sc contains more beta sheet structure than PrP^C.
C)PrP^Sc lacks the sugar residues that are attached to PrP^C.
D)PrP^Sc is not exposed on the surface of the cell.
E)PrP^Sc does not bind to copper like PrP^C does.

Question 8

Which of the following is NOT a characteristic of the PrP^C form of the prion protein?

A)It is bound to a phospholipid anchor.
B)It is synthesized in the rough ER.
C)It is glycosylated.
D)It binds to copper ions.
E)All of the above are characteristics of the PrP^C protein.

Question 9

Which of the following tests would be most useful to diagnose a prion disease in a patient?

A)MRI of the brain to detect damage.
B)CAT scan of the brain to detect damage.
C)Test for the presence of PrP^Sc protein in the tonsils.
D)Microscopically examine a brain biopsy.
E)Sequencing of the patient's prion gene.

Question 10

When it was discovered,what was surprising about the gene that codes for the prion infectious agent?

A)It is easily transmitted as naked nucleic acid.
B)It is coded for by RNA not DNA.
C)It is found in the genome of the host.
D)It has a high degree of secondary structure.
E)There is no gene that codes for the prion protein.

Question 11

All of the following demonstrate that prions do not appear to contain a nucleic acid EXCEPT:

A)Infectivity is resistant to phenol.
B)Infectivity is resistant to UV radiation.
C)Infectivity is resistant to nucleases.
D)Infectivity is resistant to high concentrations of zinc ions.
E)Infectivity is resistant to ammonium hydroxide.

Question 12

What is the proposed mechanism by which humans acquired the new variant form of Creutzfeldt-Jakob disease?

A)Humans who received blood from CJD infected donors.
B)Humans who received corneas from CJD infected donors.
C)Humans who participated in ritualistic cannibalism.
D)Humans who ate sheep infected with the scrapie agent.
E)Humans who ate cows infected with the BSE agent.

Question 13

All of the following describe the attributes that distinguish different strains of prions EXCEPT:

A)The amino acid sequence of the prion protein.
B)The size of the protease resistant portion of the prion protein.
C)The disease symptoms they cause.
D)The pattern of glycosylation on the prion protein.
E)The incubation time for the disease that they cause.

Question 14

The genetic forms of prion diseases result from mutations in the prion gene.What is the proposed mechanism for how these mutations cause the prion disease?

A)They cause the prion protein to become degraded in the cell.
B)They stabilize the structure of the PrP^C form of the protein.
C)They lead to overexpression of the prion protein in the brain.
D)They cause the prion protein to misfold more easily into the PrP^Sc form.
E)They cause the prion protein to interact with the microtubules in the neuron.

Question 15

Prions from one species do not easily cause prion diseases in animals of a different species.Which of the following may explain why?

A)The host cell needs to have the correct receptor for entry of the Prp^Sc protein.
B)The host needs to have the correct proteases for the proper processing of the PrP^Sc protein.
C)The host cell needs to provide the correct glycosylation pattern on the Prp^Sc protein.
D)The Prp^Sc protein needs to interact with a PrP^C protein with the same amino acid sequence.
E)There are other host related proteins involved in the development of a prion disease.

Question 16

The prion hypothesis has been deemed too controversial to be eligible for a Nobel Prize.

Question 17

Which of the following is the general term used to describe the type of disease caused by prions?

A)Transmissible neurodegeneration
B)Transmissible spongiform encephalopathy
C)Chronic inflammatory neuropathy
D)Creutzfeldt-Jakob disease
E)Huntington's disease

Question 18

Which of the following observations about the PrP^Sc protein could explain how this protein causes damage to the neurons of the brain?

A)The PrP^Sc protein causes glycosylation of membrane proteins to become disregulated.
B)The PrP^Sc protein causes copper to be sequestered in neurons.
C)The PrP^Sc protein is more resistant to protease digestion than the cellular form.
D)The PrP^Sc protein alters the signaling pathways in neurons.
E)The PrP^Sc protein aggregates to form fibrils.

Question 19

Which of the following experiments demonstrates that PrP^C is required for prion disease transmission?

A)Mice with the hamster PrP gene are susceptible to hamster prions.
B)Mice lacking the Prp gene are resistant to prion infections.
C)Yeast have proteins that can form self-propagating states like prion proteins.
D)The PrP^Sc protein has the same amino acid sequence as the PrP^C protein.
E)Injection of brain extracts from kuru patients into monkeys causes the monkeys to get a similar disease.

Question 20

All of the following diseases have been demonstrated to be caused by protein misfolding EXCEPT:

A)Alzheimers disease
B)Autism
C)Huntington's disease
D)Parkinson's disease
E)Cystic fibrosis

Question 21

Mice that lack the gene encoding the normal prion protein have severe neurological defects.

Question 22

Sheep that are homozygous for a specific amino acid at codon 171 of the prion gene are completely resistant to infection with scrapie.

Question 23

Describe how the prion hypothesis explains how there can be both an acquired and a genetic form of Creutzfeldt-Jakob disease.

Question 24

Explain the nucleation-polymerization model for the propagation of the PrP^Sc form of the prion protein.How does this differ from the alternative model?

Question 25

The high proportion of people who are heterozygous at codon 129 of the prion protein gene suggests that ancient humans may have participated in ritualistic cannibalism.

Question 26

Explain the observations that link new variant CJD with BSE.