Volume 8 Supplement 2

Frontiers of Retrovirology 2011

Open Access

Mov10, an APOBEC3G-interacting RNA-binding protein, inhibits HIV-1 infection

  • Shetal Arjan1,
  • Chad Swanson1,
  • Nathan Sherer1 and
  • Michael Malim1
Retrovirology20118(Suppl 2):P2

https://doi.org/10.1186/1742-4690-8-S2-P2

Published: 3 October 2011

Background

Identification of cellular factors that negatively or positively regulate HIV-1 replication is essential to understand HIV-1 pathogenesis for development of novel antiviral treatments. The human cytidine deaminase APOBEC3G (A3G) is an intrinsic antiviral factor important for the host-mediated defence against HIV-1. We and others recently identified a panel of A3G-interacting RNA-binding proteins (RBPs) that focused our search for novel HIV-1 cofactors and restriction factors onto these proteins. Mov10, a superfamily-1 putative RNA helicase, interacts with A3G in an RNA-dependent manner. Mov10 associates with the RNA-induced silencing complex pathway and localises to mRNA processing bodies (PBs). Furthermore, orthologs of Mov10 in Arabidopsis thaliana and Drosophila melanogaster are necessary for antiviral small RNA-mediated silencing. Thus, we investigated whether Mov10 restricts HIV-1 replication.

Materials and methods

The effect of Mov10 on HIV-1 virus production and ínfectivity was determined by ectopic expression and silencing of Mov10 in virus-producing HeLa and 293T cell lines. Cells were transfected with a plasmid encoding the full-length HIV-1NL4-3 provirus or infected with VSV-G pseudotyped HIV-1NL4-3 virus. Virion production was measured by p24Gag ELISA and infectivity was determined by infecting a TZM reporter cell line with virus normalised by p24Gag concentration.

Results

The ectopic expression of Mov10 substantially decreased HIV-1 virion infectivity, whilst moderately decreasing virus production. Mov10 induced a significant reduction in the accumulation of minus strand strong stop DNA in the target cell, which likely accounted for the considerable loss in virion infectivity. Preliminary results showed a small decrease in HIV-1 genome incorporation into budding virions that may have contributed to the defect at strong stop. Mov10 comprises a 495 residue amino-terminal domain with no known protein motifs, and a 508 residue carboxy-terminal putative RNA helicase domain. To begin to identify important attributes in Mov10 we mutated known helicase motifs in the full-length protein; overexpression of these mutants determined that the carboxy-terminal putative RNA helicase domain of Mov10 is necessary for its antiviral activity. Furthermore, RNAi-mediated silencing of endogenous Mov10 moderately enhanced HIV-1 virion production with no discernable effect on virion infectivity. We also tested A3G antiviral activity in the context of Mov10 silencing, which was unaffected.

Conclusions

Our findings indicate a potential antiviral role for Mov10 in the HIV-1 life cycle, independent of A3G antiviral activity. The effect of Mov10 silencing on HIV-1 was modest, however, this is currently being addressed in primary CD4+T cells and macrophages, the natural targets of HIV-1 infection. Furthermore, we are investigating whether Mov10 is upregulated by type I interferon and identifying molecular mechanism/s by which Mov10 is able to inhibit HIV-1 infection.

Authors’ Affiliations

(1)
Department of Infectious Diseases, King's College London

Copyright

© Arjan et al; licensee BioMed Central Ltd. 2011

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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