Human immunodeficiency virus 1 (taxid:11676)

Molecular biology

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Enveloped, spherical to pleomorphic in shape, 80-100 nm in diameter. Mature capsid contains 1572 capsid proteins.

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Monopartite, linear, dimeric, ssRNA(+) genome of 9,75 kb, with a 5'-cap and a 3'poly-A tail. There are two long terminal repeats (LTRs) of about 600nt long at the 5' and 3' ends. The LTRs contain the U3, R, and U5 regions. There are also a primer binding site (PBS) at the 5'end and a polypurine tract (PPT) at the 3'end.

GENE EXPRESSION

The integrated provirus utilizes the promotor elements in the 5' LTR to drive transcription. This gives rise to the unspliced full length mRNA that will serve as genomic RNA to be packaged into virions or used as a template for translation of gag and gag-(pro)pol (1 ribosomal frameshift) polyproteins. The uncompletely spliced mRNAs encode env that is cleaved into SU and TM envelope proteins, and the accessory proteins vif, vpu, and vpr. Completely spliced mRNAs encode Rev, Tat and Nef accessory proteins. Rev escorts unspliced and uncompletely spliced RNAs out of the nucleus of infected cells.

ENZYMES

REPLICATION

NUCLEAR

Lytic replication:

  1. Virus attaches to host CD4 receptors through the SU glycoprotein (gp120), with subsequent interaction with a chemokine coreceptor.
  2. Internalization via clathrin-dependent endocytosis. TM glycoprotein (gp41) mediates dynamin-dependent fusion with the host endosomal membrane. Nucleocapsid is released into the cytoplasm, with partial uncoating.
  3. ssRNA(+) genome is copied into a linear dsDNA molecule by the reverse transcriptase.
  4. Nuclear entry of the viral dsDNA which is covalently and randomly integrated into the cell's genome by the integrase (=provirus).
  5. Transcription of provirus by Pol II produces viral spliced and unspliced RNAs.
  6. Translation of spliced viral RNAs produces tat, rev, and nef proteins.
  7. Rev mediates nuclear export of the uncompletely spliced RNAs.
  8. Translation of unspliced viral RNAs produces Env, Gag and Gag-Pol polyproteins.
  9. Assembly of the virion at the host cellular membrane and packaging of the viral RNA genome.
  10. Budding through the plasma membrane and release of the virions.
  11. Proteolytic processing of the precursors polyproteins by viral protease and maturation of the virions.

Latent replication : replication as a provirus integrated in the host chromosome.

Reference strains

HIV-1 REFERENCE STRAIN HIV-1 subtype B strain HxB2
Sequence | Genome | Proteome

EXPERIMENTAL CLONE PNL4.3 pNL4-3 is a subtype B strain that is normally used as the reference sequence for HIV drug resistance studies. It is a recombinant (infectious) proviral clone that contains DNA from HIV isolates NY5 (5' half) and BRU (3' half). The site of recombination is the EcoRI site at positions 5743-5748.
Sequence | Proteome

GROUP O REFERENCE STRAIN Group O seems to be endemic and largely confined to Cameroon and neighboring countries in West Central Africa, where these viruses represent a small minority of HIV-1 strains. (Pubmed)

HIV-1 isolate ANT70
Sequence | Proteome

GROUP N REFERENCE STRAIN The group N is confined to Cameroon. (Pubmed)

HIV-1 isolate YBF30
Sequence | Proteome
GROUP M REFERENCE STRAINS

HIV-1 group M is responsible for the worlwide pandemy of AIDS. It is subdivised into 9 subtypes (A-F), and several CRF.
(Reference strains have been chosen in collaboration with Tulio de Oliveira, Bioafrica.net)

Subtype A1: HIV-1 isolate U455
Sequence | Proteome

Subtype B: HIV-1 strain HxB2
Sequence | Genome | Proteome

Subtype C: HIV-1 isolate TV001
Sequence | Proteome

Subtype D: HIV-1 isolate ELI
Sequence | Proteome

Subtype F1: HIV-1 isolate 93BR020
Sequence | Proteome

Subtype F2: HIV-1 isolate MP255
Sequence | Proteome

Subtype G: HIV-1 isolate 92BR025
Sequence | Proteome

Subtype H: HIV-1 isolate 90CF056
Sequence | Proteome

Subtype J: HIV-1 isolate SE9173
Sequence | Proteome

Subtype K: HIV-1 isolate 96CM-MP535
Sequence | Proteome

CRF01_AE: HIV-1 isolate 90CF11697
Sequence | Proteome

CRF02_AG: HIV-1 isolate 97CM.MP807
Sequence | Proteome

Epidemiology

Global map of HIV infection source WHO/UNAIDS

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HIV subtypes

HIV viruses are subdivised into groups, subtypes and CRF. Groups N and O are recent and so far restricted to cameroon. The vast majority of HIV-1 strains found worldwide belongs to Group M (Major). This group is subdivised into 9 subtypes (A-F), and several CRF (circulating recombinant form).

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Source Peeters, M.

Replication cycle

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  1. Virus attaches to host CD4 receptors through the SU glycoprotein (gp120), with subsequent interaction with a chemokine coreceptor.
  2. Internalization via clathrin-dependent endocytosis. TM glycoprotein (gp41) mediates dynamin-dependent fusion with the host endosomal membrane. Nucleocapsid is released into the cytoplasm, with partial uncoating.
  3. ssRNA(+) genome is copied into a linear dsDNA molecule by the reverse transcriptase.
  4. Nuclear entry of the viral dsDNA which is covalently and randomly integrated into the cell's genome by the integrase (=provirus).
  5. Transcription of provirus by Pol II produces viral spliced and unspliced RNAs.
  6. Translation of spliced viral RNAs produces tat, rev, and nef proteins.
  7. Rev mediates nuclear export of the uncompletely spliced RNAs.
  8. Translation of unspliced viral RNAs produces Env, Gag and Gag-Pol polyproteins.
  9. Assembly of the virion at the host cellular membrane and packaging of the viral RNA genome.
  10. Budding through the plasma membrane and release of the virions.
  11. Proteolytic processing of the precursors polyproteins by viral protease and maturation of the virions.

Matching UniProtKB/Swiss-Prot entries

(all links/actions below point to uniprot.org website)

0 entry grouped by protein