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Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells
Published on: January 30, 2019
The cellular source for APOBEC3G's incorporation into HIV-1
1Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing, PR China.
Retrovirology
|January 8, 2011
Summary
Lipid raft-associated APOBEC3G (hA3G) complexes are identified as the cellular source for viral hA3G. This finding clarifies the mechanism of hA3G virion encapsidation, crucial for its anti-HIV activity.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Background:
- Human APOBEC3G (hA3G) inhibits HIV-1 infectivity.
- hA3G virion incorporation is essential for its antiviral function.
- The cellular origin of virion-incorporated hA3G is not well understood.
Purpose of the Study:
- To investigate the cellular source of virally incorporated human APOBEC3G (hA3G).
- To elucidate the mechanism of hA3G complex formation and its role in virion encapsidation.
Main Methods:
- Analysis of hA3G molecular complexes (LMM and HMM).
- Investigation of hA3G interaction with membrane lipid raft domains.
- Site-directed mutagenesis to study hA3G complex formation and viral incorporation.
Main Results:
- Newly synthesized hA3G interacts with lipid rafts, forming Lipid raft-associated hA3G (RA hA3G).
- RA hA3G acts as a precursor to mature high-molecular-mass (HMM) hA3G complexes.
- A subset of hA3G remains as soluble low-molecular-mass (LMM) form in the cytoplasm.
- N-terminal linker region and C-terminus regulate hA3G distribution.
- hA3G's ability to form RA LMM complexes directly correlates with its viral incorporation.
Conclusions:
- Lipid raft-associated LMM A3G complexes serve as the cellular source of viral hA3G.
- This identifies a key step in the pathway of hA3G incorporation into HIV-1 virions.
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