Deck 23: Adenoviruses

Question 1

The proteins produced from which of the following genes from adenovirus serves to suppress apoptosis in infected cells?

A)E1A
B)E1B
C)E2
D)E3
E)Major late gene

Answer 1

B

Question 2

Binding of histone deacetylases to the promoters of genes leads to activation of transcription from that promoter.

Answer 2

False

Question 3

If the E1A gene is transfected into cultured cells,it causes an abortive transformation and the cells die.If the E1B gene is included with E1A,then cells become fully transformed and survive.What critical function does the E1B gene provide?

A)The E1B proteins suppress apoptosis.
B)The E1B proteins prevent the degradation of the p53 protein.
C)The E1B proteins assist with transport of mRNAs out of the nucleus.
D)The E1B proteins bind to Rb and cause the cell to enter S phase.
E)The E1B proteins activate transcription from p53 inducible promoters.

Answer 3

A

Question 4

The E2 gene encodes all of the following proteins involved in replicating the adenovirus genome EXCEPT:

A)DNA polymerase
B)Preterminal protein.
C)Single-stranded DNA binding protein.
D)Ligase
E)All of these proteins are encoded by the E2 gene.

Question 5

Which component of the adenovirus virion binds to the host cell receptor?

A)Knob on the fiber protein.
B)Penton base.
C)Hexons.
D)Minor capsid proteins.
E)Both "a" and "b" can bind to different receptors.

Question 6

During the cell cycle in an uninfected cell,the cellular protein Rb represses S phase genes by doing which of the following?

A)Localizes histone deacetylase to E2F inducible genes.
B)Binds to the adenovirus E1A protein and releases E2F.
C)Prevents binding of the cellular RNA polymerase II to E2F inducible genes.
D)Binds and phosphorylates the cyclin dependent kinase.
E)Prevents the binding of E2F to the promoters of S phase genes.

Question 7

There are five families of mature transcripts produced from the major late gene of adenovirus.Which of the following is the MAJOR determinant for which family is produced from the primary transcript?

A)The location of the polyadenylation site.
B)The location of the 5' splice site.
C)The location of the 3' splice site.
D)The location of the transcription start site.
E)The location of the start codon.

Question 8

All of the following are involved in determining the type of mRNAs produced during adenovirus infection EXCEPT…..

A)Transcription initiation by RNA polymerase II.
B)Location of the transcriptional promoters.
C)Location of the start codons.
D)Alternative mRNA splicing.
E)Alternative polyadenylation sites.

Question 9

The E1A protein from adenovirus indirectly stabilizes the cellular p53 protein.Why is this potentially a problem for the virus?

A)This will activate the adaptive immune response against virally infected cells.
B)This will initiate the RNAi pathway,which leads to degradation of viral RNA.
C)This will induce the apoptosis pathway,which leads to cell death.
D)The virus requires active p53 protein to activate viral genes.
E)The virus does not use p53,so this is not a problem at all.

Question 10

During DNA replication of the adenovirus genome,the virus only uses continuous synthesis,which means that it does not produce Okazaki fragments.

Question 11

Adenovirus virions are composed of which of the following components?

A)Hexons composed of trimers of the hexon protein.
B)Penton bases composed of five copies of the penton protein.
C)Penton fibers composed of trimers of polypeptide IV.
D)Basic polypeptides bound to the viral DNA.
E)All of the above are correct.

Question 12

Which of the following describes the function of the terminal protein in the replication of the genome of adenovirus?

A)It ligates the viral genome into a circular molecule.
B)It produces the RNA primer.
C)It binds single-stranded DNA and prevents reannealing.
D)It acts as the primer for DNA replication.
E)It acts as the DNA polymerase.

Question 13

During infection with adenovirus which of the following events activates the production of the major late transcripts?

A)Entry of the viral genome into the nucleus.
B)Replication of the viral genome.
C)Transcription of the E1A gene.
D)Transcription of the E1B gene.
E)Transcription of the E2 gene.

Question 14

Adenovirus virions are transported to the nucleus of the host cell via an interaction between the hexon proteins and which of the following cellular structures?

A)Nuclear matrix
B)Microtubules
C)Actin fibers
D)Intermediate filaments
E)Endocytotic vesicles.

Question 15

What is the structure of the ends of the adenovirus genome when it is released from the virion into the nucleus?

A)There are no ends - the viral genome is a closed circle.
B)There is a single 5' phosphate.
C)There is a triphosphate at the 5' end.
D)The terminal protein is covalently bound to the 5' end.
E)The ends are paired to each other in a panhandle formation.

Question 16

Which of the following was NOT studied or discovered in adenoviruses?

A)mRNA splicing
B)Transcription initiation by RNA polymerase II
C)Regulation of protein translation.
D)Proteins involved in regulating transcription.
E)Use of viruses as gene therapy vectors.

Question 17

The tripartite leader found on all of the transcripts produced from the major late gene of adenovirus carries out which of the following functions?

A)It makes the mRNA more stable.
B)It binds to the eIF4F translation factor.
C)It shunts the ribosome to the correct AUG on the mRNA.
D)It assists with transport of the mRNA out of the nucleus.
E)It improves the efficiency of mRNA splicing.

Question 18

What is the function of the VA RNAs produced by adenovirus?

A)Inhibition of the cellular RNA polymerase III.
B)Inhibition of the interferon induced PKR kinase.
C)Stimulation of translation of viral mRNAs.
D)Regulation of mRNA stability.
E)Inhibition of the adaptive immune system.

Question 19

The E1A protein from adenovirus can act as an oncogene by inducing tumors in experimental animals.

Question 20

The CR3 region,found on the13S version of the E1A protein,is involved in activation of transcription by binding to which of the following proteins?

A)CBP
B)TBP
C)ATF
D)CBP and TBP
E)ATF and TBP

Question 21

A strain of adenovirus,called ONYX-015,that does not express the E1B 55K protein,is being studied as a treatment for cancer.Why does the lack of E1B 55K allows this virus to spread and kill cancer cells but not normal cells?

Question 22

Transcription from the major late promoter of adenovirus produces a primary transcript that is over half the length of the virus genome.

Question 23

When rodent cells are infected with adenovirus,they produce virions and are killed by the virus.

Question 24

The unique 5' cap and 3' poly(A)tail in the late transcripts of adenovirus allow the ribosome to begin translation at the correct start codon.

Question 25

Adenovirus has a linear double-stranded DNA genome.Describe how adenovirus DNA is replicated so that the "end problem" is solved.

Question 26

Because adenovirus produces all of the enzymes it needs for DNA replication,it is not dependent on the host cell entering the S phase of the cell cycle.