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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
APOBEC3 proteins and reverse transcription.
Renato S Aguiar1, B Matija Peterlin
1Department of Medicine, Microbiology and Immunology, University of California, San Francisco (UCSF), 533 Parnassus Avenue U422, San Francisco, CA 94143-0703, USA.
Virus Research
|February 12, 2008
Summary
APOBEC3 (A3) proteins provide intrinsic immunity against viruses like HIV by deaminating viral DNA. They also inhibit viral replication through non-deaminase activity, protecting the genome from pathogens and mobile elements.
Area of Science:
- Immunology
- Virology
- Molecular Biology
Background:
- APOBEC3 (A3) proteins are known to confer intrinsic immunity against retroviral infections.
- These proteins function as cytidine deaminases (CDAs), inducing hypermutation in viral genomes.
- A3 proteins restrict HIV replication, though this is counteracted by the viral infectivity factor (Vif).
Purpose of the Study:
- To elucidate the multifaceted mechanisms by which APOBEC3 proteins inhibit viral replication.
- To explore the non-cytidine deaminase functions of A3 proteins in antiviral defense.
- To understand the broader implications of A3 proteins in protecting the host genome.
Main Methods:
- Analysis of A3 protein interactions with viral components.
- Biochemical assays to assess cytidine deaminase (CDA) activity.
- Studies investigating A3 protein inhibition of reverse transcriptase (RT) activity.
Main Results:
- A3 proteins exhibit cytidine deaminase (CDA) activity, causing hypermutation in retroviral genomes.
- A3 proteins also inhibit viral replication independently of CDA activity by interfering with reverse transcriptase (RT) catalyzed DNA elongation.
- These dual mechanisms provide robust intracellular immunity against various viruses and mobile genetic elements.
Conclusions:
- APOBEC3 proteins are critical components of the innate immune system, offering broad protection against viral pathogens.
- The dual mechanism of action, involving both CDA activity and direct inhibition of reverse transcriptase, highlights the versatility of A3 proteins in host defense.
- A3 proteins play a significant role in safeguarding the host genome from exogenous retroviruses and endogenous mobile elements.
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