papillomaviruses and retroviruses Flashcards

exam 4

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1
Q

Pervasive. Nearly everyone will be infected with an HPV at some point in their lifetime

A

papillomavirus

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2
Q

non-enveloped, icosahedral with a 8kb, circular dsDNA

A

Papillomavirus

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3
Q

papillomaviruses initially attach to ________ on the basement membrane

A

heparan sulfate proteoglycans

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4
Q

papillomaviruses infections begin in

A

basal layer

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5
Q

papillomaviruses enter by

A

receptor-mediated endocytosis

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6
Q

papillomavirus is trafficked to late endosomes, similar to picornaviruses but

A

caspid disassembles in the endosome

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7
Q

gene expression is tightly coupled to differentiation state of

A

epithelial cells

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8
Q

is the master regulator of viral gene expression by directing synthesis of other early mRNAs including E6 and E7

A

E2

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9
Q

early synthesis of _____ and ____ mRNA using cell-specific promoter and differential splicing

A

E1 and E2

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10
Q

binds p53, preventing cell death by apoptosis

A

E6

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11
Q

binds Rb and other proteins stimulating entry into the cell cycle

A

E7

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12
Q

directs initiation of DNA replication

A

E2

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13
Q

viral genome is mantained at a

A

high copy number

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14
Q

late gene expression occurs only in terminally differentiated

A

keratinocytes

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15
Q

keratinocyte differentiation activates late promoter and

A

stimulates DNA replication

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16
Q

differential splicing to give mRNAs for

A

L1 and L2 capsid proteins

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17
Q

Transport of L1 and L2 proteins to nucleus for

A

assembly into caspid

18
Q

virions do not __________, they are released by normal ketatinocyte death and loss membrane integrity

A

lyse the cell

19
Q

those that will rise to a cancer will have E6 and E7 but not

A

E2

20
Q

replicate through a DNA intermediate (provirus) integrated into the host genome

A

retroviruses

21
Q

enveloped single stranded (+) RNA, 1-10 kb

A

retrovirus

22
Q

____ polyprotein forms virion. structural protein

A

Gag

23
Q

retrovirus embedded in viral membrane ; glycoprotein

A

Env

24
Q

viral enzymes: protease, reverse transcriptase and integrase

A

pol

25
Q

in a retrovirus the virion must contains the viral enzyme

A

RT
PR
IN

26
Q

reverse transcription in a retrovirus occurs

A

immediately upon entry

27
Q

in retroviruses, DNA form of the genome is trafficked to the nucleus, where

A

the entire genome is integrated into the host genome by the viral integrase

28
Q

synthesis of (-) DNA to 5-end using host

A

tRNA primer

29
Q

finish product in reverse transcription

A

double DNA provirus integrated into genome

30
Q

in reverse trancription, difference btween RNA genome and DNA genome

A

ends are different in RNA but in DNA it is the same

31
Q

retrovirus DNA integration carried out by

A

viral integrase

32
Q

simple retrovirus require

A

cell division

33
Q

complex retrovirus (HIV) traffic

A

mRNAs out to ctoplasm

34
Q

mRNA requires splicing

A

Env

35
Q

unspliced mRNA is used to express

A

Gag and Pol

36
Q

new virion is not infectious until it

A

matures

37
Q

maturation step in which these polyprotein are cleaved int their constituent proteins by viral peptidases

A

Gag and Pro

38
Q

1 mechanism of transformation

A

proviral DNA integrates into the genome upstream of a proto-oncogene–> LTR can deregulate the Proto-oncogene and forming it into an oncogene

39
Q

2 mechanism of transformation

A

retrovirus contain the proto-oncogene in its genome; any cell infected will become cancerous

40
Q

Identify between retrovirus and papillomavirus:

  1. integration is part of a normal replication cycle
  2. integration is a rare chance event and not part of normal virus life cycle
A
  1. retrovirus

2. papillomavirus

41
Q

Identify between retrovirus and papillomavirus:

  1. oncogene product interacts with members of the pathway that stimulates cells into S-phase DNA synthesis
  2. Many of the same oncogenes are altered by mutation in non-viral human cancers
A
  1. papillomaviruses

2. retroviruses

42
Q

Identify between retrovirus and papillomavirus:

  1. oncogenes are viral genes
  2. oncogene can be either in virus or cell genome
A
  1. papillomavirus

2. retroviruses