| Structural highlights
Function
[ABC3F_HUMAN] DNA deaminase (cytidine deaminase) which acts as an inhibitor of retrovirus replication and retrotransposon mobility via deaminase-dependent and -independent mechanisms. Exhibits antiviral activity against vif-deficient HIV-1. After the penetration of retroviral nucleocapsids into target cells of infection and the initiation of reverse transcription, it can induce the conversion of cytosine to uracil in the minus-sense single-strand viral DNA, leading to G-to-A hypermutations in the subsequent plus-strand viral DNA. The resultant detrimental levels of mutations in the proviral genome, along with a deamination-independent mechanism that works prior to the proviral integration, together exert efficient antiretroviral effects in infected target cells. Selectively targets single-stranded DNA and does not deaminate double-stranded DNA or single- or double-stranded RNA. Exhibits antiviral activity also against hepatitis B virus (HBV), equine infectious anemia virus (EIAV), xenotropic MuLV-related virus (XMRV) and simian foamy virus (SFV) and may inhibit the mobility of LTR and non-LTR retrotransposons. May also play a role in the epigenetic regulation of gene expression through the process of active DNA demethylation.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
Publication Abstract from PubMed
The HIV-1 Vif protein inactivates the cellular antiviral cytidine deaminase APOBEC3F (A3F) in virus-infected cells by specifically targeting it for proteasomal degradation. Several studies identified Vif sequence motifs involved in A3F interaction, whereas a Vif-binding A3F interface was proposed based on our analysis of highly similar APOBEC3C (A3C). However, the structural mechanism of specific Vif-A3F recognition is still poorly understood. Here we report structural features of interaction interfaces for both HIV-1 Vif and A3F molecules. Alanine-scanning analysis of Vif revealed that six residues located within the conserved Vif F1-, F2-, and F3-box motifs are essential for both A3C and A3F degradation, and an additional four residues are uniquely required for A3F degradation. Modeling of the Vif structure on an HIV-1 Vif crystal structure revealed that three discontinuous flexible loops of Vif F1-, F2-, and F3-box motifs sterically cluster to form a flexible A3F interaction interface, which represents hydrophobic and positively charged surfaces. We found that the basic Vif interface patch (R17, E171, and R173) involved in the interactions with A3C and A3F differs. Furthermore, our crystal structure determination and extensive mutational analysis of the A3F C-terminal domain demonstrated that the A3F interface includes a unique acidic stretch (L291, A292, R293, and E324) crucial for Vif interaction, suggesting additional electrostatic complementarity to the Vif interface compared with the A3C interface. Taken together, these findings provide structural insights into the A3F-Vif interaction mechanism, which will provide an important basis for development of novel anti-HIV-1 drugs using cellular cytidine deaminases. IMPORTANCE: HIV-1 Vif targets cellular antiviral APOBEC3F (A3F) enzyme for degradation. However, the details on the structural mechanism for specific A3F recognition remain unclear. This study reports structural features of interaction interfaces for both HIV-1 Vif and A3F molecules. Three discontinuous sequence motifs of Vif, F1, F2, and F3 boxes, assemble to form an A3F interaction interface. In addition, we determined a crystal structure of the wild-type A3F C-terminal domain responsible for the Vif interaction. These results demonstrated that both electrostatic and hydrophobic interactions are the key force driving Vif-A3F binding and that the Vif-A3F interfaces are larger than the Vif-A3C interfaces. These findings will allow us to determine the configurations of the Vif-A3F complex and to construct a structural model of the complex, which will provide an important basis for inhibitor development.
Structural Insights into HIV-1 Vif-APOBEC3F Interaction.,Nakashima M, Ode H, Kawamura T, Kitamura S, Naganawa Y, Awazu H, Tsuzuki S, Matsuoka K, Nemoto M, Hachiya A, Sugiura W, Yokomaku Y, Watanabe N, Iwatani Y J Virol. 2015 Nov 4;90(2):1034-47. doi: 10.1128/JVI.02369-15. PMID:26537685[14]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wiegand HL, Doehle BP, Bogerd HP, Cullen BR. A second human antiretroviral factor, APOBEC3F, is suppressed by the HIV-1 and HIV-2 Vif proteins. EMBO J. 2004 Jun 16;23(12):2451-8. Epub 2004 May 20. PMID:15152192 doi:10.1038/sj.emboj.7600246
- ↑ Chen H, Lilley CE, Yu Q, Lee DV, Chou J, Narvaiza I, Landau NR, Weitzman MD. APOBEC3A is a potent inhibitor of adeno-associated virus and retrotransposons. Curr Biol. 2006 Mar 7;16(5):480-5. PMID:16527742 doi:10.1016/j.cub.2006.01.031
- ↑ Delebecque F, Suspene R, Calattini S, Casartelli N, Saib A, Froment A, Wain-Hobson S, Gessain A, Vartanian JP, Schwartz O. Restriction of foamy viruses by APOBEC cytidine deaminases. J Virol. 2006 Jan;80(2):605-14. PMID:16378963 doi:10.1128/JVI.80.2.605-614.2006
- ↑ Zielonka J, Bravo IG, Marino D, Conrad E, Perkovic M, Battenberg M, Cichutek K, Munk C. Restriction of equine infectious anemia virus by equine APOBEC3 cytidine deaminases. J Virol. 2009 Aug;83(15):7547-59. doi: 10.1128/JVI.00015-09. Epub 2009 May 20. PMID:19458006 doi:10.1128/JVI.00015-09
- ↑ Mbisa JL, Bu W, Pathak VK. APOBEC3F and APOBEC3G inhibit HIV-1 DNA integration by different mechanisms. J Virol. 2010 May;84(10):5250-9. doi: 10.1128/JVI.02358-09. Epub 2010 Mar 10. PMID:20219927 doi:10.1128/JVI.02358-09
- ↑ Paprotka T, Venkatachari NJ, Chaipan C, Burdick R, Delviks-Frankenberry KA, Hu WS, Pathak VK. Inhibition of xenotropic murine leukemia virus-related virus by APOBEC3 proteins and antiviral drugs. J Virol. 2010 Jun;84(11):5719-29. doi: 10.1128/JVI.00134-10. Epub 2010 Mar 24. PMID:20335265 doi:10.1128/JVI.00134-10
- ↑ Stenglein MD, Burns MB, Li M, Lengyel J, Harris RS. APOBEC3 proteins mediate the clearance of foreign DNA from human cells. Nat Struct Mol Biol. 2010 Feb;17(2):222-9. doi: 10.1038/nsmb.1744. Epub 2010 Jan , 10. PMID:20062055 doi:10.1038/nsmb.1744
- ↑ Guo JU, Su Y, Zhong C, Ming GL, Song H. Hydroxylation of 5-methylcytosine by TET1 promotes active DNA demethylation in the adult brain. Cell. 2011 Apr 29;145(3):423-34. doi: 10.1016/j.cell.2011.03.022. Epub 2011 Apr, 14. PMID:21496894 doi:10.1016/j.cell.2011.03.022
- ↑ Hultquist JF, Lengyel JA, Refsland EW, LaRue RS, Lackey L, Brown WL, Harris RS. Human and rhesus APOBEC3D, APOBEC3F, APOBEC3G, and APOBEC3H demonstrate a conserved capacity to restrict Vif-deficient HIV-1. J Virol. 2011 Nov;85(21):11220-34. doi: 10.1128/JVI.05238-11. Epub 2011 Aug 10. PMID:21835787 doi:10.1128/JVI.05238-11
- ↑ Phalora PK, Sherer NM, Wolinsky SM, Swanson CM, Malim MH. HIV-1 replication and APOBEC3 antiviral activity are not regulated by P bodies. J Virol. 2012 Nov;86(21):11712-24. doi: 10.1128/JVI.00595-12. Epub 2012 Aug 22. PMID:22915799 doi:10.1128/JVI.00595-12
- ↑ Refsland EW, Hultquist JF, Harris RS. Endogenous origins of HIV-1 G-to-A hypermutation and restriction in the nonpermissive T cell line CEM2n. PLoS Pathog. 2012;8(7):e1002800. doi: 10.1371/journal.ppat.1002800. Epub 2012 Jul, 12. PMID:22807680 doi:10.1371/journal.ppat.1002800
- ↑ Chaipan C, Smith JL, Hu WS, Pathak VK. APOBEC3G restricts HIV-1 to a greater extent than APOBEC3F and APOBEC3DE in human primary CD4+ T cells and macrophages. J Virol. 2013 Jan;87(1):444-53. doi: 10.1128/JVI.00676-12. Epub 2012 Oct 24. PMID:23097438 doi:10.1128/JVI.00676-12
- ↑ Gillick K, Pollpeter D, Phalora P, Kim EY, Wolinsky SM, Malim MH. Suppression of HIV-1 infection by APOBEC3 proteins in primary human CD4(+) T cells is associated with inhibition of processive reverse transcription as well as excessive cytidine deamination. J Virol. 2013 Feb;87(3):1508-17. doi: 10.1128/JVI.02587-12. Epub 2012 Nov 14. PMID:23152537 doi:10.1128/JVI.02587-12
- ↑ Nakashima M, Ode H, Kawamura T, Kitamura S, Naganawa Y, Awazu H, Tsuzuki S, Matsuoka K, Nemoto M, Hachiya A, Sugiura W, Yokomaku Y, Watanabe N, Iwatani Y. Structural Insights into HIV-1 Vif-APOBEC3F Interaction. J Virol. 2015 Nov 4;90(2):1034-47. doi: 10.1128/JVI.02369-15. PMID:26537685 doi:http://dx.doi.org/10.1128/JVI.02369-15
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