APOBEC3G inhibits elongation of HIV-1 reverse transcripts.

APOBEC3G (A3G) is a host cytidine deaminase that, in the absence of Vif, restricts HIV-1 replication and reduces the amount of viral DNA that accumulates in cells. Initial studies determined that A3G induces extensive mutation of nascent HIV-1 cDNA during reverse transcription. It has been proposed...

Full description

Bibliographic Details
Main Authors: Kate N Bishop, Mohit Verma, Eun-Young Kim, Steven M Wolinsky, Michael H Malim
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2008-12-01
Series:PLoS Pathogens
Online Access:http://europepmc.org/articles/PMC2584787?pdf=render
Description
Summary:APOBEC3G (A3G) is a host cytidine deaminase that, in the absence of Vif, restricts HIV-1 replication and reduces the amount of viral DNA that accumulates in cells. Initial studies determined that A3G induces extensive mutation of nascent HIV-1 cDNA during reverse transcription. It has been proposed that this triggers the degradation of the viral DNA, but there is now mounting evidence that this mechanism may not be correct. Here, we use a natural endogenous reverse transcriptase assay to show that, in cell-free virus particles, A3G is able to inhibit HIV-1 cDNA accumulation not only in the absence of hypermutation but also without the apparent need for any target cell factors. We find that although reverse transcription initiates in the presence of A3G, elongation of the cDNA product is impeded. These data support the model that A3G reduces HIV-1 cDNA levels by inhibiting synthesis rather than by inducing degradation.
ISSN:1553-7366
1553-7374