6 - Rotavirus and Enteroviruses

Question 1

Where do rotaviruses fit on the Baltimore classification scheme?

Answer 1

Class III

Question 2

Where do enteroviruses fit on the Baltimore classification scheme?

Answer 2

Class IV

Question 3

What is the viral enterotoxin in rotavirus called and what does it do?

Answer 3

NSP4 - causes Cl ion release

Question 4

How does rotavirus replication occur?

Answer 4

1. dsRNA synthesised by RdRp
2. mRNAs are capped and exported to the cytoplasm
3. mRNAs translated by host ribosomes.

Question 5

How does rotavirus assembly occur?

Answer 5

1. Vira proteins aggregate in the cytoplasm driving formation of RdRp containing nucleocapsids.
2. (+)ssRNA strands taken up by nucleocapsid cores
3. Complementary (-)ssRNA synthesised by RdRp in nucleocapsid cores
4. Viral capsid proteins added by ER
5. Mature virions released

Question 6

How does poliovirus production of viral proteins occur?

Answer 6

1. VPg is cleaved enabling direct translation of viral RNA by host ribosomes.
2. Translated as single polyprotein which is cleaved into smaller proteins with different functions
3. Production of RdRp

Question 7

How does poliovirus genome synthesis / replication occur?

Answer 7

1. Viral RdRp uridylates VPg
2. uridylated VPg recognises poly A tail of viral genome acting as a primer for replication.
3. (-)ssRNA strand is produced.