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Flashcards in RNA 2 Deck (15):
1

List the respiratory viruses.

Picorna- (rhino, some entero)
Paramyxo
Orthomyxo
Corona
Adeno (naked DNA)

2

Influenza

orthomyxo family
enveloped, helical, negative strand, ss
naturally infect a variety of species

3

RNA Segments for Influenza A

1, 2, 3, 5, 8 = non-structural
4 = hemagluttinin, attachment
6 = neuramininidase, virus release
7 = matrix (M1, M2 proteins) = genome export, M2 important for getting genome out

4

Why are viral surface proteins important?

1. Entry & Release
2. Targets of neutralizing Abs

5

Hemagglutinin

binds sialic acid for ATTACHMENT AND ENTRY of virus
trimer, highly variable AA sequence
HA0 = cleaved by cellular proteases in resp. epithelium into HA1, HA2
HA 1 = attachment
HA 2 = fusion

6

HA 1

attachment

7

HA 2

fusion

8

Neuraminidase

cleaves sialic acid during release (when virus exits cell)
tetramer, spreading factor by dissolving mucus
allows for viral budding/spreading by cleaving virus from excess sialic acid and mucus
critical for release of virus from cell

9

Neuraminidase is target for which drugs?

Tamiflu, Relenza

10

Subtypes of HA, NA

18, 3 in humans
11, 2 in humans

11

What is the fusion peptide?

the newly formed amino terminal of HA2 is hydrophobic and inserts into endosomal membrane to initiate fusion with the viral envelope

12

M1

matrix

13

M2

ion channel/nuclear pore

14

Galactose + Sialic Acid 2 Different Linkages

Alpha (2,3) linkage -- cleavage in LOWER RT -- avian
Alpha (2,6) linkage -- cleavage in UPPER RT -- human

15

Antiviral Drugs for Influenza

Amantadine & Rimantadine = A only, targets M2 ion channel and blocks virion fusion -- stops viral spread

Zanamivir (Relenza) & Oseltamavir (Tamiflu) = A&B, target virus release by inhibiting NA -- cant dump its genome