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Updated: May 24, 2026

Measurement of In Vitro Integration Activity of HIV-1 Preintegration Complexes
Published on: February 22, 2017
[HIV-1 assembly is initiated by p17 matrix protein]
Abstract:
HIV-1 matrix protein (MA) is multifunctional structural protein located on N-terminus of Gag precursor p55 and responsible for its transport to plasma membrane, the site of virus assembly. Here, it has been shown that MA is cleaved from Gag precursor at early stage of the virus infection and participates in virus assembly. MA is transported into the nuclei wherein it associates with viral RNA (vRNA). The MA-vRNA complex is transported to plasma membrane. Mutant MA which lost its membranotropic signal does not reach plasma membrane and MA-vRNA complex remains in the nuclei and cytoskeleton. Thus, MA seems to deliver vRNA from the nuclei to plasma membrane through cytoskeleton initiating virus assembly.
Insights
HIV-1 matrix protein (MA) delivers viral RNA (vRNA) from the nucleus to the plasma membrane, initiating virus assembly. This transport relies on MA's membranotropic signal and the cytoskeleton.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Context:
- The human immunodeficiency virus type 1 (HIV-1) matrix protein (MA) is a key structural component.
- MA is essential for transporting the Gag precursor polyprotein (p55) to the plasma membrane for virus assembly.
Purpose:
- To elucidate the role and transport mechanism of HIV-1 matrix protein (MA) in viral assembly.
- To investigate the interaction of MA with viral RNA (vRNA) and its pathway within infected cells.
Summary:
- HIV-1 MA is cleaved from the Gag precursor early in infection and plays a crucial role in virus assembly.
- MA is transported to the nucleus, where it binds to vRNA, forming a complex.
- This MA-vRNA complex is then transported to the plasma membrane via the cytoskeleton, a process dependent on MA's membranotropic signal.
Impact:
- Identifies a novel pathway for vRNA transport mediated by MA.
- Highlights the importance of MA's membranotropic signal in HIV-1 assembly.
- Provides insights into the molecular mechanisms of retroviral replication and assembly.
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