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Updated: Jun 10, 2026
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Interview: HIV-1 Proviral DNA Excision Using an Evolved Recombinase
Published on: June 17, 2008
Death by deamination: a novel host restriction system for HIV-1
1Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Columbia University College of Physicians and Surgeons, 701 West 168th Street, New York, NY 10032, USA. goff@cancercenter.columbia.edu
Cell
|August 14, 2003
Summary
A newly discovered human gene encodes a cytidine deaminase enzyme that fights viral DNA synthesis in infected cells. However, the HIV-1 Vif gene counteracts this host defense, enabling viral replication.
Area of Science:
- Biochemistry
- Virology
- Immunology
Background:
- Cytidine deaminases are known for roles in mRNA editing and immunoglobulin gene diversification.
- A novel human gene has been identified with significant antiretroviral properties.
Purpose of the Study:
- To characterize a new human gene encoding a cytidine deaminase with antiretroviral activity.
- To understand the mechanism by which this enzyme restricts viral replication.
- To investigate the role of the HIV-1 Vif gene in overcoming this host defense.
Main Methods:
- Gene identification and characterization.
- Enzyme activity assays.
- Viral DNA synthesis analysis in infected cells.
- Analysis of HIV-1 Vif protein function.
Main Results:
- The identified human gene encodes a cytidine deaminase that targets newly synthesized viral DNA.
- This enzymatic activity prevents the formation of functional proviruses.
- The Vif protein of HIV-1 effectively antagonizes this host restriction mechanism.
- HIV-1 replication is permitted when the Vif gene is functional.
Conclusions:
- A human cytidine deaminase acts as a potent intrinsic defense against retroviral infection by degrading viral DNA.
- The HIV-1 Vif protein is crucial for viral replication as it overcomes this host-mediated antiretroviral activity.
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