Related Experiment Video

Updated: Aug 8, 2026

Imaging of HIV-1 Envelope-induced Virological Synapse and Signaling on Synthetic Lipid Bilayers
11:45

Imaging of HIV-1 Envelope-induced Virological Synapse and Signaling on Synthetic Lipid Bilayers

Published on: March 8, 2012

Early intermediates in HIV-1 envelope glycoprotein-mediated fusion triggered by CD4 and co-receptor complexes

A S Dimitrov1, X Xiao, D S Dimitrov

  • 1Laboratory of Experimental and Computational Biology, Center for Cancer Research, NCI, National Institutes of Health, Frederick, Maryland 21702, USA.

The Journal of Biological Chemistry
|June 9, 2001
PubMed

Insights

HIV-1 entry involves envelope glycoprotein (GP120-GP41) activation. This process destabilizes HIV-1 Env-expressing cell membranes, initiating fusion and offering targets for new entry inhibitors.

Area of Science:

  • Virology
  • Cell Biology
  • Biochemistry

Background:

  • Human immunodeficiency virus type 1 (HIV-1) entry into target cells is a complex process initiated by the envelope glycoprotein (GP120-GP41).
  • GP120-GP41 must transition to a fusogenic state upon binding to target cell CD4 and a co-receptor to facilitate viral entry.

Purpose of the Study:

  • To investigate the early membrane events during HIV-1 envelope-mediated fusion.
  • To identify potential targets for novel HIV-1 entry inhibitors.

Main Methods:

  • Incubation of HIV-1 Env-expressing cells with target cells or CD4.co-receptor complexes on beads.
  • Monitoring dye influx into Env-expressing cells as an indicator of membrane permeabilization.
  • Assessing the effect of co-receptor ligands and GP41 peptide inhibitors on permeabilization.

Main Results:

  • HIV-1 Env-expressing cells showed dye influx and permeabilization upon incubation with CD4 and co-receptor-bearing target cells, correlating with cell fusion.
  • Permeabilization was also induced by CD4.co-receptor complexes on beads, independent of target cells.
  • This permeabilization exhibited co-receptor specificity and was blocked by natural co-receptor ligands and GP41 peptide inhibitors.

Conclusions:

  • HIV-1 envelope-mediated fusion is initiated by the destabilization of the viral envelope-expressing cell membrane.
  • Understanding these early membrane intermediates is crucial for developing inhibitors of HIV-1 entry.

More Related Videos

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay07:10

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay

Published on: September 14, 2014

Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes10:34

Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes

Published on: February 22, 2017

Related Concept Videos

Retrovirus Life Cycles01:10

Retrovirus Life Cycles

Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to...
SNAREs and Membrane Fusion01:43

SNAREs and Membrane Fusion

Once a transport vesicle has recognized its target organelle, the vesicular membrane needs to fuse with the target membrane to unload the cargo. Transmembrane proteins called SNAREs present on organelle membranes and their vesicles, mediate vesicle fusion.
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
Immune Response Against Viral Pathogens01:29

Immune Response Against Viral Pathogens

The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses.
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
Size and Structure of Viral Genomes01:26

Size and Structure of Viral Genomes

Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
Inhibitors of Virion Maturation and Assembly01:19

Inhibitors of Virion Maturation and Assembly

As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...