Related Experiment Video

Updated: Aug 8, 2026

Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites
09:31

Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites

Published on: March 22, 2016

Oligomerization within virions and subcellular localization of human immunodeficiency virus type 1 integrase

C Petit1, O Schwartz, F Mammano

  • 1Unité d'Oncologie Virale, Institut Pasteur, Paris, France.

Journal of Virology
|May 11, 1999
PubMed

Insights

Researchers visualized human immunodeficiency virus type 1 (HIV-1) integrase protein (IN) oligomers within virions using epitope tagging. This confirmed IN multimerization is essential for viral infectivity and disulfide bridge formation.

Area of Science:

  • Virology
  • Molecular Biology
  • Structural Biology

Background:

  • Previous studies suggested retroviral integrase protein (IN) functions as a multimer.
  • Direct evidence for IN oligomerization during the viral infectious cycle was lacking due to insufficient detection methods.

Purpose of the Study:

  • To develop a sensitive method for detecting human immunodeficiency virus type 1 (HIV-1) integrase (IN) oligomerization during infection.
  • To investigate the role of IN oligomerization in viral infectivity and its dependence on disulfide bridges.

Main Methods:

  • Generation of infectious HIV-1 viral clones engineered to express epitope-tagged IN.
  • Visualization of tagged IN in producer cells and viral particles using epitope detection.
  • Analysis of IN oligomer formation, its dependence on disulfide bonds, and the impact of cysteine mutations on infectivity.

Main Results:

  • Epitope-tagged IN was successfully visualized in producer cells and viral particles, enabling direct detection of IN oligomers.
  • IN oligomerization was confirmed to occur within virions and depend on disulfide bridges.
  • Mutation of a conserved cysteine residue critical for dimerization abolished viral infectivity and reduced IN oligomer formation.

Conclusions:

  • Epitope tagging of HIV-1 IN provides a powerful tool to study its function during the viral cycle.
  • IN oligomerization, dependent on disulfide bridges, is crucial for HIV-1 infectivity.
  • These findings validate the importance of IN multimerization in viral replication.

More Related Videos

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

Assembly and Purification of Prototype Foamy Virus Intasomes10:20

Assembly and Purification of Prototype Foamy Virus Intasomes

Published on: March 19, 2018

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...
Retroviruses02:33

Retroviruses

Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
Intralumenal Vesicles and Multivesicular Bodies01:38

Intralumenal Vesicles and Multivesicular Bodies

Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
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 Release01:25

Inhibitors Of Virion Release

Viral replication and dissemination rely on efficient mechanisms for host cell entry, genome replication, assembly, and release. Influenza viruses, such as types A and B, are negative-sense single-stranded RNA viruses with a segmented genome, that depend on two critical surface glycoproteins to carry out these processes: hemagglutinin (HA) and neuraminidase (NA). HA initiates infection by binding to sialic acid residues on the surface of host epithelial cells, facilitating receptor-mediated...
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...