Related Experiment Video

Updated: Aug 11, 2025

Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle GUV Membranes
08:21

Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle GUV Membranes

Published on: July 28, 2016

9.0K

Early HIV-1 Gag Assembly on Lipid Membrane with vRNA

Anne X-Z Zhou, John A Hammond, Kai Sheng

    Biorxiv : the Preprint Server for Biology
    |February 7, 2023
    PubMed

    Insights

    Mass photometry revealed HIV-1 Gag assembly initiates with trimerization on membranes, requiring vRNA. Oligomer growth occurs monomer by monomer, supporting a gradual capsid lattice formation model.

    Area of Science:

    • Virology
    • Biophysics
    • Structural Biology

    Background:

    • Human Immunodeficiency Virus type 1 (HIV-1) assembly is a complex process crucial for viral replication.
    • Understanding the initial steps of Gag polyprotein assembly is key to developing antiviral strategies.

    Approach:

    • Mass photometry (MP) was employed to study the assembly of myristoylated Gag (myr-Gag) and viral RNA (vRNA) 5' UTR in a supported lipid bilayer (SLB) model.
    • MP allowed for real-time, single-molecule analysis of Gag-Gag and Gag-vRNA interactions.

    Key Points:

    • Gag trimerization on the membrane is a critical early event in HIV-1 assembly, dependent on the presence of vRNA.
    • Oligomerization proceeds through the addition of one or two Gag monomers at a time from solution, requiring vRNA.
    • These findings support a model of capsid lattice formation initiated by trimeric nucleation followed by gradual edge expansion.

    Conclusions:

    • The study provides novel insights into the dynamic, single-molecule mechanisms governing the initiation of HIV-1 capsid assembly.
    • This research highlights the interplay between Gag protein, vRNA, and lipid membranes in initiating viral structure formation.

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