9.2 COVID Flashcards
molecule on the surface of sar-cov-2
spike glycoprotein, M protein, E-protein
function of spike protein
binds to ACE2 host receptor for entry into the cell
- undergoes conformational change to release its fusion peptide into the host plasma membrane
what other molecule is needed to enter the virus by fusion
host proteases to cleave the spike protein to undergo conformational change to release its fusion peptide into the host plasma membrane
types of host proteases
- proprotein convertases> furin
- cell surface proteases
- lysosomal proteases
can sars-cov enter the cell by endocytosis
yes by ACE2 receptor only
how does endocytosis occur
s protein binds to ACE 2
- triggers endocytosis
- S protein activates in endosome by furin
- endosome formed and fuses with emebrane
- release of viral RNA into cytoplasm
how does direct fusion occur
S protein binds to ACE2 receptor
-cleaved by furin and TMPRSS2
-release of internal fusion eptide
fusion with membrane
what is Antibody dependent enchancement
where the virus bidns to a AB
- that AB binds to a host receptor
- forms endosome with the virus in it in the host cell
what is complement casade for cov entry
the virus binds to a complement protein and that binds tot he host receptor
- forms endosome
- leads to viral replication
what happens during viral repilcation
as usual
-viral RNA translated into a polyprotein
which are celaved by viral rpoteases
where does the viral proteins rpdouced from
replicase transcriptase complex (RTC) in double membrane vesciles
what does RTC have
contain RdRp to mediate viralRNA replication for protein synthesis
what type of virus is covid
ss+RNA
how to produce large numbers of +RNA genomes
ss-RNA used as a template
where does the replication of the virus happen
in the cytoplasm
