HIV

Question 1

Structure consists of?

Answer 1

1. Envelope

2. Capsid

Question 2

Envelope contains?

Answer 2

-Gp120: surface glycoproteins; bind to CD4

-Gp41: transmembrane glycoproteins
-> confirmation changes
=> fusion

Question 3

Capsid contains?

Answer 3

• integrate
• protease
• reverse transcriptase

Question 4

Function of RT?

Answer 4

• RDDP

- > transcribes ssRNA(+) into cDNA

Question 5

Function of integrase

Answer 5

Insert cDNA into host cell’s DNA

Question 6

Function of protease

Answer 6

-cleave immature virus glycoproteins @assembly

Question 7

Describe attachment and penetration

Answer 7

Gp120 binds to CD4 receptor
-> conformation change;

• > bind to
  1. CCR5 (macrophage)
  2. CXCR4 (Th)

-> expose gp41;
-> pierce; contract and pull
-> membrane fusion
=> releasing virus nucleocapsid

Question 8

Describe uncoating

Answer 8

• virus capsid is degraded by enzymes in cytoplasm

- > releasing contents

Question 9

Describe reverse transcription and integration

Answer 9

•ssRNA(+) transcribe into cDNA (RT)

-> RNA (degraded)
} hybrid
-> DNA (synthesis another DNA)

=> dsDNA inserted into chromosomal DNA of host cell; provirus

Question 10

Describe synthesis

Answer 10

Provirus

1) dormant
2) px virus RNA and new virus proteins

• transcribe provirus gene into (+)ssRNA genome; by host cell RNA polymerase

Question 11

@synthesis

What is the ssRNA(+) molecules used for?

Answer 11

1. ssRNA(+) genome for new virus particles
2. mRNA for
   a) translation into immature, non-fn virus polyprotein

b) translation into glycoproteins

Question 12

Describe assembly

Answer 12

HIV protease cleaves immature, non-fn virus polyprotein into individual functional proteins and enzymes

-> spontaneous self assemble into new virus nucleocapsid

Question 13

Describe release

Answer 13

@budding