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Amplification of Near Full-length HIV-1 Proviruses for Next-Generation Sequencing
Published on: October 16, 2018
Functional redundancy in HIV-1 viral particle assembly
Ina P O'Carroll1, Rachael M Crist, Jane Mirro
1HIV Drug Resistance Program, National Cancer Institute, Frederick, Maryland, USA.
Journal of Virology
|September 21, 2012
Summary
HIV-1 Gag protein assembly into virus-like particles (VLPs) requires membrane binding, capsid dimerization, and RNA binding. Any two of these functions are sufficient for partial assembly, indicating redundancy in Gag
Area of Science:
- Virology
- Molecular Biology
- Biochemistry
Background:
- Retroviral Gag proteins drive virus particle assembly.
- In vitro, Gag proteins assemble into virus-like particles (VLPs) with nucleic acids.
- Gag conformational changes at high local concentrations are proposed as essential for assembly.
Purpose of the Study:
- To investigate the roles of specific HIV-1 Gag functions in virus particle assembly in human cells.
- To determine the necessity and redundancy of membrane binding, capsid dimerization, and RNA binding for Gag assembly.
Main Methods:
- Characterization of HIV-1 Gag mutants with defects in plasma membrane binding, capsid dimerization, or RNA binding.
- Analysis of virus-like particle (VLP) assembly in human cells expressing these Gag mutants.
Main Results:
- Gag mutants with a single defect retained partial assembly capability into spherical structures.
- Combinations of any two defects completely abolished Gag assembly into VLPs.
- The three studied Gag functions appear redundant for initial Gag molecule concentration.
Conclusions:
- Plasma membrane binding, capsid dimerization, and RNA binding are individually partially dispensable for HIV-1 Gag assembly.
- These functions act redundantly, with any two sufficient to support some level of assembly.
- Gag's ability to concentrate itself via these mechanisms is crucial for initiating virus particle formation.
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