Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MIMM 324 > 14. Adenovirus 1 > Flashcards

14. Adenovirus 1 Flashcards

1
Q

what happens when adenovirus is injected in rodents?

A

causes cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

does adenovirus cause cancer in humans? why?

A

no –> virus kills cells and we have immune response against it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

is adenovirus enveloped?

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

describe the shape and size of adenovirus

A

icosahedral with fibres sticking out –> 90nm in diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

3 characteristics of the genome

A
  1. dsDNA
  2. 35-45 kb
  3. linear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the family name of adenoviruses?

A

adenoviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what genus of adenoviridae infect humans?

A

Mastadenovirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

who are most at risk for adenovirus?

A

military recruits, boarding schools, infants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how many adenovirus types are there? how many infect humans?

A

> 100 adenovirus types identified, 50 infect humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are 3 types of diseases caused by adenovirus?

A
  1. Respiratory infection
  2. Conjunctivitis
  3. Gastrointestinal infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which 2 types of adenovirus cause the most severe cases of respiratory illness

A

4 and 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where does adenovirus replicate in the cell? how do we know?

A

in nucleus

can detect inclusion bodies in nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does the virus life cycle progress in 16h?

A

once the virus enters, can make 10,000 copies in 16h

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does adenovirus induce in human kidney tissue culture cells?

A

cytopathic effects (CPE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can we purify adenovirus?

A

with CsCl density gradient

gives us specific band

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the biggest and most abundant viral protein?

A

hexon protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

describe the placement of hexon

A

in the capsid, has 6 other copies around it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

besides hexon, what is the other major capsid protein?

A

penton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe the placement of penton

A

associated with fibre protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is within the capsid?

A

a core that holds the genome

21
Q

what is the role of VII protein?

A

acts as histones, surrounding DNA

22
Q

what is the role of VI protein?

A

associates the outer hexon/penton structure with the core

23
Q

discovery of what part of the genome won a nobel prize?

A

splicing! –> mRNAs look different than genome

24
Q

why does the adenovirus life cycle cause cancer?

A

infects upper respiratory tract where cells aren’t dividing and forces cells to replicate so it can replicate its genome –> forces them to become cancer

25
Q

how did scientists find that adenovirus uses splicing?

A

annealed the genome with mRNA –> pieces of genomic DNA were looped out –> these are introns that are spliced out

26
Q

what are the 2 unique features on the end of the adenovirus genome?

A
  1. terminal protein
  2. nucleotide repeat
27
Q

describe the terminal protein

A

covalently linked to 5’ end via phosphodiester link

28
Q

describe the nucleotide repeats

A

they are complementary, can fold back on itself

29
Q

how does adenovirus enter cells?

A

virus enters epithelium via microlesions and binds Coxsackie B virus and Adenovirus Receptor (CAR) and breaks epithelial layer

30
Q

what are CAR receptors used for normally?

A

used in cell-cell adhesion in tight junctions

31
Q

describe the 6 stages of the virus from cell entry to nuclear entry

A
  1. fibres bind CAR
  2. penton binds integron
  3. enters as coated vesicle
  4. enters endosome and capsid is broken down
  5. travels thru cytoplasmic via microtubules
  6. imports DNA into nucleus via nuclear pore complex
32
Q

what happens to the virus in the endosome?

A

endosome acidifies and activates protease to break protein VI and release the core

33
Q

what is the first gene transcribed? what is its role?

A

E1A –> transcription factor

34
Q

what genes does E1A turn on?

A

E1B, E2, E3, E4

35
Q

what are the 2 types of E1A protein?

A
  1. 289R
  2. 243R
36
Q

what is the difference btwn 289R and 243R?

A

289R has conserved region 3 (CR3)

37
Q

describe CR3
- 2 functions

A
  1. binds DNA so E1A can increase activity TATA box binding protein
  2. binds DNA so E1A can increase activity of cell cycle promoters
38
Q

what is the similarity and difference in function between 289R and 243R?

A

similarity: both very oncogenic

difference: without CR3, E1A cannot turn on E1B, E2, E3, E4

39
Q

what is E2F?

A

activates S phase genes

40
Q

3 examples of S phase genes:

A
  1. DNA pol
  2. nucleotide synthesis enzymes
  3. cyclins required for progression thru cell cycle
41
Q

how does E1A affect E2F?

A

ACTIVATES transcription

42
Q

describe how E1A activates E2F transcription

A

normally Rb binds E2F to repress S phase genes when cells not dividing

but E1A binds and sequesters Rb so E2F can be active to activate S phase and E2 genes

43
Q

how is E2F transcription normally activated when the cell wants to divide?

A

Cdk cell cycle protein phosphorylates Rb so E2F is free

44
Q

why is Rb such an important molecule?

A

it is the decision point between G1 and S phase –> past this point, the cell must commit to replication

45
Q

what are the 3 functional domains of E1A in both 289R and 243R?

A
  1. N
  2. CR1
  3. CR2
46
Q

what 2 proteins interact with N and CR1 domain?

A
  1. p300
  2. CBP
47
Q

what type of protein are p300 and CBP? and their 2 roles

A

Histone acetyltransferases (HAT)

stimulate transcription for:
1. stimulating viral gene expression
2. allow cells to stay in differentiated state

48
Q

what happens with E1A binds p300 and CBP?

A

E1A inhibits cell differentiation thru binding p300/CBP

49
Q

How does E1A inhibit cell differentiation by binding p300/CBP?

A

p300 and CBP acetylate histones which relaxes the histone/DNA complex formation –> this allows increased gene expression for cell differentiation and allows cell cycle arrest

but when E1A binds p300 and CBP, cell differentiation is inhibited and cell can continue proliferating

MIMM 324 (37 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions