adenovirus

Question 1

True or false: cells with only E1B will enter the cell cycle but they will end up dying

Answer 1

true

Question 2

what do IVa2 and 52/55k do

Answer 2

IVa2 is an intermediate gene and 52/55k is a late gene
basically what they do is they are atpases motors that will help put the viral genome into the capsid

Question 3

is VARNA a coding sequence and what does it do

Answer 3

it is a non-coding sequence and it blocks the interferon pathway aka it blocks the immune response

Question 4

True or false: E!A turns on expression of early promoters through 289R and 243R

Answer 4

true

Question 5

true or false: E3 is not an immmune modulator

Answer 5

false: he is an immune modulator

Question 6

what does 33k and 100k do

Answer 6

they are chaperones/scaffolds for capsid assembly

Question 7

what do 11.6k and orf 3/4 do?

Answer 7

INDUCE APOPTOSIS AT THE completion of the viral life cycle
-lysys=helps the cell go out
if no 11.6k= cells are full of virus but it can’t get out

Question 8

why did richard roberts and philip sharp win the noble prize

Answer 8

they won it in 1993 for their discoveries of split genes

Question 9

true or false: the viral genome of adenoviruses has cellular histones

Answer 9

true but it also has viral proteins on their genomes

Question 10

why does a virus want oncogenes

Answer 10

because depending on where the virus infect the cells ex: epithelial cells
they don’t replicate, they don’t divide because they are already differentiated
viruses develop proteins that regulate replication and push the cells into S phase

Question 11

Top which family p300 and CBP are in

Answer 11

HATS

Question 12

what is the main role of the RB family

Answer 12

it is a tumor suppressor, if mutated=cancer

Question 13

what happens if there are mutations in CR1 and 2

Answer 13

the proteins made won’t bind to RB and then E1A can’t keep the S phase

Question 14

why is the N terminus important in adenoviruses

Answer 14

if it gets peeled off E1A is less effective= the TFs produced have more difficulty activating viral genes and the S phase

Question 15

Why is RB blocks at the G1?

Answer 15

-it is between the “real” start point aka go or no go decision
-RB is the real gatekeeper of the cell cycle progression
boundary between G1 and S phase
-sensitive to growth factors

Question 16

What happens if E2F is turned on?

Answer 16

things that are regulated by it will also be turned on like DNA pol and genes for nucleotide synthesis

Question 17

How does E1A inhibits cell differenciation?

Answer 17

-through binding of p300 and CBP
-p300 and CBP (cAMP binding proteins) are related cellular proteins which have histone-acetyltransferase (HAT) activity
-Acetylation of histones induces chromatin modification resulting in increased gene expression due to relaxing of histone/DNA complex formation
- Acetylation of histones results in the expression of genes involved in various cellular functions including cell differentiation.
-Differentiation mediates cell cycle arrest

Question 18

what are the most important proteins for replication in adenovirus

Answer 18

-viral dna pol
-terminal protein
-dna binding protein

Question 19

explain how adenovirus replicates

Answer 19

adeno virus ppt page 25

Question 20

what are the roles of the terminal repeats in adeno virus

Answer 20

it is so that the og strand that is left alone can bp with itself to make some type of loop then the DNA pol can synthesize a new strand

Question 21

true or false: there is always the tripartite leader in the mrna of adenovirus

Answer 21

true

Question 22

how is the adenovirus able to take one long strand of DNA and then make a lot of proteins

Answer 22

alternative splicingggg

Question 23

what is the role of the p14 arf gene

Answer 23

-tumor suppresor
-when E2F is upregulated it’ll recognize that it is def sus
-p14 arf will then bind to MDM (which is usually bound to P53 aka best tumor suppressor and MDM destabilize the p53
-when 53 is off from MDM it is more stable and will induce apoptosissss
-if there is like UV or weird chemicals then it’ll also stabilize p53

Question 24

how does E1A induce apoptosis

Answer 24

it binds to MDM and then p53 is stable= apoptosisss

Question 25

what is the role of E1B-55k gene

Answer 25

-it inhibits p53 through complex formation
-it binds to p53 and then there is cell survival in presence of E1A
-because when you wanna infect a cell you need E1A for 0starting S phase and then you can inhibit p53

Question 26

true or false: there are clinical trials for making adenoviruses into oncolytic virus

Answer 26

yes
you modify the viorus so that there is no E1B 55k so it can’t mess with p53=only replicates in cancer cells where p53 is mutated
-it’ll then replicate and then will lyse the cells

Question 27

which gene in adenoviruses has homology with cellular bcl2

Answer 27

-E1B-19k so it inhibits cellular apoptosis
it kinda shifts the cellular balance so that bax and p53 are less powerful

Question 28

hat is the role of VA RNA

Answer 28

it binds to PKR which is important for viral sensing, if it sense drrna it’ll phosphorylate then phosphorylate elF2a which’ll shut down the translation
-by binding tightly to PKR it inhibits it
-it also binds to dicer which is important for making micrornas and exportin-s so it blocks the nuclear export of pre-mirna
-dicer inhibits viral replication of adenovirus
-pkr also binds to dicer so no mirna is made

Question 29

t is the role of E3 in adenoviruses

Answer 29

the E3 region is in charge of downregulation the immune response
-it downregulates the TNF receptor and TRAIL which are involved with T cell killing virus infected cells
-GP19k also internalizes the MHC which is usually used by infected cells to show off peptides to say that they are infected