Deck 15: Paramyxo-Viruses and Rhabdoviruses

Question 1

Which of the following virion proteins mediates the coiling of the rhabdovirus nucleocapsid to form the bullet-shaped virion?

A) The HN (hemagglutinin/neuraminidase) protein
B) The F (fusion) protein
C) The M (matrix) protein
D) The N (nucleocapsid) protein
E) The L (RNA polymerase) protein

Answer 1

C

Question 2

What is the function of the neuraminidase enzyme during infection with Sendai virus, a member of the paramyxovirus family?

A) It helps the assembly of the envelope.
B) It attaches to the host cell receptor.
C) It is involved in evasion of the host immune system.
D) It facilitates exit of the virions.
E) It is involved with transcription of viral mRNAs.

Answer 2

D

Question 3

Rhabdoviruses can infect a wide variety of hosts including insects, plants and vertebrates.

Answer 3

True

Question 4

The F protein of the paramyxovirus measles is responsible for both binding and fusion of the virion to the host cell.

Question 5

New paramyxoviruses have emerged from fruit bats by being transmitted to domestic livestock and then to humans.

Question 6

How is the poly(A)tail added to the 3' ends of the mRNAs produced during infection with a paramyxovirus?

A) The viral polymerase stutters at a poly(U) sequence.
B) The cellular poly(A) polymerase adds it.
C) Paramyxovirus mRNAs do not have poly(A) tails.
D) The viral poly(A) polymerase adds it after the mRNA is released from the template.
E) The entire poly(A) tail is encoded in the genome.

Question 7

Which of the following describes a major difference between the positive-strand RNA viruses and negative-strand RNA viruses?

A) Only positive-strand viruses must package their polymerase in their virion.
B) Only negative-strand viruses must package their polymerase in their virion.
C) Only positive-strand viruses must encode a polymerase in their genome.
D) Only negative-strand viruses must encode a polymerase in their genome.
E) Both kinds of RNA viruses both encode and package a polymerase.

Question 8

Synthesis of mRNAs in paramyxoviruses occurs through a single-entry mechanism, which is where the RNA-dependent RNA polymerase can only start transcription from the 3' end of the genome.Which of the following is a consequence of this mechanism?

A) More negative-strand genomes are produced than positive-strand antigenomes.
B) The RNA-dependent RNA polymerase binds to both end of the genome for genome replication
C) The RNA-dependent RNA polymerase binds to both ends of the genome for transcription
D) More mRNA is produced from the coding regions at the 5' end of the genome.
E) More mRNA is produced from the coding regions at the 3' end of the genome.

Question 9

Which of the following statements about rabies is FALSE?

A) The virion has a bullet shape.
B) It is usually transmitted through the bites of bats or domestic dogs.
C) The vaccine can be administered after infection has occurred.
D) Infection with the virus has a 50% mortality rate in untreated individuals.
E) Infection of humans causes an encephalitis.

Question 10

Which of the following is a difference observed between the paramyxoviruses and the rhabdoviruses?

A) One has a negative-strand genome and one has a positive-strand genome.
B) One has a naked virion and one has an enveloped virion.
C) One has a helical nucleocapsid and one has an icosahedral nucleocapsid.
D) One packages the RNA-dependent RNA polymerase and the other doesn't.
E) One fuses the envelope at the plasma membrane and one fuses the envelope with the endocytotic membrane.

Question 11

All of the following viruses are members of the order Mononegavirales EXCEPT….

A) Rabies
B) Influenza
C) Measles
D) Ebola
E) Sendai virus

Question 12

Which of the following statements about paramyxoviruses is FALSE?

A) The N protein can bind to a variable number of nucleotides in the genome.
B) The RNA-dependent RNA polymerase is a virion protein.
C) Every protein coded for in the genome is packaged into the virion
D) The N protein protects the genome from ribonuclease digestion.
E) Naked genome-length RNA is never found within the cell.

Question 13

There are two sequence elements at the 3' end of the genomes of paramyxoviruses that are required for mRNA transcription and genome replication.These two sequences are 78 nucleotides apart.How can the polymerase bind to both of these sequence elements at the same time?

A) There are cellular proteins that bridge the two sequences.
B) There are viral proteins that bridge the two sequences.
C) The two sequences are both on the same side of the helical nucleocapsid.
D) The polymerase protein is large enough to bind both sequences.
E) The polymerase does not need to bind to both sequences simultaneously.

Question 14

Mutation of the RNA editing site in the genome of a paramyxovirus will have which of the following effects?

A) It eliminates the production of the P protein.
B) It eliminates the production of the V protein.
C) It causes the production of the P protein.
D) It causes the production of the V protein
E) It eliminates mRNA splicing.

Question 15

Which of the following proteins from paramyxovirus virions interacts with the tails of the envelope glycoproteins during assembly of virions?

A) N protein
B) C protein
C) L protein
D) M protein
E) F protein

Question 16

What mechanism do the paramyxoviruses use to produce 5 different proteins from a single gene on their genome?

A) Use of alternative start codons.
B) Read-through of a stop codon.
C) Ribosomal frameshifting
D) RNA editing
E) Both RNA editing and alternative start codons are used.

Question 17

Which of the following describes the process of RNA editing as used by the paramyxoviruses?

A) Removal of an introns and splicing together of the exons.
B) Splicing together of two separate RNAs.
C) Removal of one or two nucleotides from the 5' end of the mRNA.
D) Addition of one or two non-template nucleotides to the mRNA.
E) Removal of one or two nucleotides from the middle of the mRNA.

Question 18

In the paramyxoviruses, cleavage of the F0 protein into two subunits F1 and F2 is important for which of the following?

A) Formation of the envelope.
B) Glycosylation of the protein.
C) Creation of the transmembrane domain.
D) Exposing the fusion peptide.

Question 19

Which of the following statements about the leader sequence at the 3' end of the paramyxovirus genome, is FALSE?

A) It is translated into a short polypeptide.
B) It is transcribed into a short positive-strand RNA.
C) The transcript produced from the leader contains a packaging signal for the positive-strand antigenome.
D) It contains the binding site for the RNA polymerase to begin transcription.
E) The transcript produced from the leader lacks a 5' cap.

Question 20

Which of the following conditions during infection with a paramyxovirus causes the RNA-dependent RNA polymerase to switch from start-stop transcription to production of full-length positive-strand antigenomes?

A) Levels of the mRNAs transcribed.
B) Concentration of the N protein.
C) Proteolytic cleavage of the polymerase protein.
D) Phosphorylation of the polymerase protein.
E) Levels of the L protein.

Question 21

Because measles virus can infect B and T lymphocytes, it can lead to strong immunosuppression.

Question 22

The order of the genes in the genomes of paramyxoviruses and rhabdoviruses is highly conserved.Is there a benefit to the virus for this specific gene order?

Question 23

Subacute sclerosing panencephalitis (SSPE)is a common complication of measles where the virus infects the nervous tissue immediately after causing the typical measles virus symptoms.

Question 24

Describe the two models that explain how the monopartite negative-strand RNA viruses produces individual mRNAs.Which of the two models does the experimental evidence support?

Question 25

Most of the genomes of the paramyxoviruses have been shown to have genomes lengths that are exact multiple of 8 nucleotides.

Question 26

Describe two major differences between transcription and genome replication in paramyxoviruses.