Antiviral immunity III Flashcards
(21 cards)
What parts of the virus life cycle do ISGs target
All
What do IFITM proteins restrict of the virus life cycle
Entry- restrict virus fusion events
What has SARS-CoV2 evovled to avoid restriction by IFITM proteins
Novel spike cleavage site, insertion in spike protein which allows cleavage by TMPRSS2 and so endosomal avoidance
What is PKR
Protein kinase R
What does PKR bind to
dsRNA
How does PKR do to eIF2-alpha and what does it form, blocking what process
eIF2-alpha, forms tight complex with GFP-eIFb, blocks translation
What virus does K3L come from
Vaccinia
What does K3L acts as to inhibit PKR
A pseudosubstrate
What does K3L exhibit homology to in order to inhibit PKR
eIF-2alpha
How does K3L inhibit PKR
Acts a psuedosubstrate replacing eIF-2 alpha and irreversibly binds to PKR
What is Viperin
Virus inhibitory ER associated interferon inducible
What does viperin localise, two places
ER and lipid droplets
What viruses does viperin disturb
RNA viruses esp Flaviviruses
What is Viperin localisation mediated by
amphipatic helix
What is Viperin homologous to
SAM enzymes which modify RNA
What does Viperin catalyse
conversion of cytidine triphosphate into analogue ddhCTP in a SAM domain-dependent manner.
Why do bacteria encode viperin homologues
Anti-phage activity
Cells are permessive and non-permessive to what virus, what protein does this relate to
HIV - Vpu
What is tetherin expression stimulated by
Interferons
Function of tetherin
Blocks envelope virus release
What is tetherin antagonised by
Vpu
