Influenza 2 Flashcards
(38 cards)
what does haemagluttinin bind to on host cell
-sialic acid
what does haemagluttinin binding to sialic acid signal
endocytosis
by what mechanism does virion enter the cell
micropinocytosis
what is the virion contained in within the host cell
endosome
what host mechanism should be defensive but is beneficial to virion
-hydrogen ions and protease
how does the virion use H+ and protease
-M2 channel allows H+ to enter virion
-acidic environment causes shedding of protein coat
what protein is unshelled when the virion is acidic
M1 matrix protein from the nucleocapsid
how is a bridge between the virion and cytoplasm made
phospholipid bilayer of virion fuses with endosome
what happens to the RNA once the M1 protein is no longer associated
-ve RNA migrate out of virion into cytoplasm
what does the exposed nucleocapsid act as
a localisation signal that helps facilitate transfer of -ve RNA into nucleus
through what does -ve RNA enter the nucleus
importin alpha and beta
what does RNA-dependent RNA polymerase facilitate the formation of
cRNA
what does the -ve viral RNA use from the host pre-mRNA
-7-methylguanin 5’ cap
why does the -ve viral RNA use the cap from host pre-mRNA
crucial for generation of +ve RNA
*allows RNA polymerase to start transcription
what is added to the +ve viral mRNA that signals it is ready for translation
poly-adenine tail
how does the host cap on viral RNA allow translation
binds to the host ribosome
How does neuraminidase aid release
-cleaves the new virion from sialic acid receptors
How is re-infection into same host cell prevented
-sialic acid receptors are cleaved by neuraminidase
how are viral proteins taken to the cell membrane
-made and processed in rough ER
-budding to the golgi body
-vesicle fuses with host cell membrane
Treatments for influenza target what (3)
-M2 ion channel inhibitor
-NA inhibitor
-viral mRNA synthesis
What treatments target M2 ion channel
Rimantadine and amantadine
At what stage do NA inhibitors stop influenza
inhibit the release stage
NA inhibitors examples
-zanamivir
-laninamivir
-peramivir
what to drugs the stop viral mRNA synthesis prevent
Cap snatching ability of RNA-dependent RNA polymerase
