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20 Cards in this Set
- Front
- Back
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Define monosystromic |
The ability to code for only 1 virus protein |
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Influenza Virus is an example of? |
Segmented negative strand RNA |
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In general each piece of negative strand RNA is monosystromic except. Why does this occur? |
Genomes 7 and 8, produced by alternate splicing |
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What 2 RNA segments are really important for how we classify influenza virus A types? What proteins do they encode? |
RNA Segment 4; Encodes protein HA RNA Segment 6; Encodes protein NA |
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HA is a protein that is encoded by RNA segment 4. What does it stand for, what is it and what does it do specifically? |
Hemagglutinin Major surface glycoprotein Receptor binding, Mediates membrane fusion at low pH, antigenic determinant |
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NA is a protein that is encoded by RNA segment 6. What is this short for, what is it and what does it do specifically? |
Neuraminidase Major surface glycoprotein Receptor destruction, dissociation of virus aggregates, antigenic determinant |
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Both HA and NA are involved in? |
Release of progeny virions from the surface of cell in the budding process. |
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What is a serotype? |
Virus strains that show differential antibody activity |
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What are 2 forms of influenza virion pleiomorphy? |
Spherical (efficient at spreading from person-to-person) Filamentous (efficient at spreading from one cell to another) |
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What viral components are present in an orthomyxovirus virion? |
The HA and NA glycoproteins 1 copy of each negative strand RNA genome segments Multiple copies of 3 submits of viral RNA-dependent RNA polymerase (RdRp) |
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Which influenza protein is responsible for receptor binding? |
Hemagglutinin |
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This glycoprotein is not involved in the entry process however, it cleaves sialic acid and is involved in the release of progeny virions from the cell surface. |
Neuraminidase |
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After endocytosis what role does the M2 proton channel play? |
It forms tetramers the create small pores in the envelope, upon acidification of the endosomes forms ion channel that allows H+ ions inside the virion. This drives the release of viral Nucleocapsid from the virion into the cytoplasm upon membrane fusion. |
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What is unusual about orthomxoviruses replication? |
They replicate in the nucleus |
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Influenza viruses do not have to encode their own capping enzyme why is this? |
They steal 5' caps from mRNA |
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What results in polyadenlation in influenza virus? |
Stuttering transcription |
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What is the most abundant viral protein in infected cells that has multiple functions to shut down the host cell? |
NS1 |
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What are the multiple functions NS1 uses to shut down the host cell? |
Interferes with polyadenlation Suppresses interferon induction |
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Which influenza A pandemic had the highest number of casualties? |
1918 Spanish Flu |
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T/F: Highly pathogenic avian influenza viruses are so alarming because they spread efficiently person-to-person. |
FALSE |
