Binding and entry of HIV virion

Summary
Organism
Homo sapiens (human)
Reactome
R-HSA-173107
PubChem
R-HSA-173107
Description
  • HIV enters cells by fusion at the cell surface, that results in a productive infection. The envelope (Env) protein of HIV mediates entry. Env is composed of a surface subunit, gp120, and a transmembrane subunit, gp41, which assemble as heterotrimers on the virion surface.The trimeric, surface gp120 protein (SU) on the virion engages CD4 on the host cell, inducing conformational changes that promote binding to select chemokine receptors CCR5 and CXCR4.
    The sequential interplay between SU, CD4 and chemokine coreceptors prompts a conformational change in the transmembrane gp41. This coiled coil protein, assembled as a trimer on the virion membrane, springs open to project three peptide fusion domains that 'harpoon' the lipid bilayer of the target cell. A hairpin structure (also referred to as a "coiled coil bundle") is subsequently formed when the extracellular portion of gp41 collapses, and this hairpin formation promotes the fusion of virion and target cell membranes by bringing them into close proximity. Virion and target cell membrane fusion leads to the release of HIV viral cores into the cell interior.
Click on a node on the pathway to see its details. Glycoproteins are marked with a glycoprotein icon in their name.
Displaying all 5 entries
UniProt ID Protein Name Gene Symbol Pathway Viewer
P01730 T-cell surface glycoprotein CD4
  • CD4
view
P04578 Envelope glycoprotein gp160
  • env
view
P51681 C-C chemokine receptor type 5
  • CCR5
  • CMKBR5
view
P61073 C-X-C chemokine receptor type 4
  • CXCR4
view
P62937 Peptidyl-prolyl cis-trans isomerase A
  • CYPA
  • HEL-S-69p
  • PPIA
view

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Acknowledgements

Supported by JST NBDC Grant Number JPMJND2204

Partly supported by NIH Common Fund Grant #1U01GM125267-01


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