Evolutionarily conserved and non-conserved retrovirus restriction activities of artiodactyl APOBEC3F proteins

Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
Nucleic Acids Research (Impact Factor: 9.11). 02/2006; 34(19):5683-94. DOI: 10.1093/nar/gkl721
Source: PubMed


The APOBEC3 proteins are unique to mammals. Many inhibit retrovirus infection through a cDNA cytosine deamination mechanism. HIV-1 neutralizes this host defense through Vif, which triggers APOBEC3 ubiquitination and degradation. Here, we report an APOBEC3F-like, double deaminase domain protein from three artiodactyls: cattle, pigs and sheep. Like their human counterparts, APOBEC3F and APOBEC3G, the artiodactyl APOBEC3F proteins are DNA cytosine deaminases that locate predominantly to the cytosol and can inhibit the replication of HIV-1 and MLV. Retrovirus restriction is attributable to deaminase-dependent and -independent mechanisms, as deaminase-defective mutants retain significant anti-retroviral activity. However, unlike human APOBEC3F and APOBEC3G, the artiodactyl APOBEC3F proteins have an active N-terminal DNA cytosine deaminase domain, which elicits a broader dinucleotide deamination preference, and they are resistant to HIV-1 Vif. These data indicate that DNA cytosine deamination; sub-cellular localization and retrovirus restriction activities are conserved in mammals, whereas active site location, local mutational preferences and Vif susceptibility are not. Together, these studies indicate that some properties of the mammal-specific, APOBEC3-dependent retroelement restriction system are necessary and conserved, but others are simultaneously modular and highly adaptable.

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    • "As a result, the viral DNA and/or RNA is degraded (LaRue et al., 2009). Therefore, the evolutionary pressure against retroviruses has been really high (Jónsson et al., 2006; Münk et al., 2010). This evolutionary pressure could explain the high variability of the A3Z1 gene. "
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    ABSTRACT: The Apolipoprotein B mRNA-editing catalytic polypeptide-like 3 (APOBEC3) genes are able to inhibit the replication of a wide range of exogenous retroviruses, as well as endogenous retroviruses and retrotransposons. Three APOBEC3 genes, named APOBEC3Z1, APOBEC3Z2 and APOBEC3Z3, have been described in sheep. In this work the three genes have been screened in order to identify polymorphisms. No polymorphism was detected for the A3Z2 and A3Z3 genes but 16 SNPs and a 3-bp deletion were found in the A3Z1 gene. A thermoestability prediction analysis was applied to the detected amino acidic SNPs by three different programs. This analysis revealed a number of polymorphisms that could affect the protein stability. The SNPs of the 3'UTR were tested to detect alterations on the predicted microRNA target sites. Two new microRNA target sites were discovered for one of the alleles. Two SNPs were selected for association studies in relation with the retroviral disease Visna/Maedi in Latxa and Assaf sheep breeds. Although association analyses resulted unconclusive, probably due to the unsuitability of the SNP allele frequency distribution of the selected polymorphisms in the analyzed breeds, these genes remain good candidates for association studies. Copyright © 2014 Elsevier B.V. All rights reserved.
    Full-text · Article · Nov 2014 · Veterinary Immunology and Immunopathology
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    • "Thus APOBEC3 family members are potentially powerful mutators [33] and very likely cells possess mechanisms to keep the latent deleterious activity of APOBEC3 in check. One way that cells protect their genomes from APOBEC3 is that mouse APOBEC3 and most human APOBEC3 proteins are localized to the cytoplasm [14,29,34]. "
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    ABSTRACT: The RNA binding protein DEAD-END (DND1) is one of the few proteins known to regulate microRNA (miRNA) activity at the level of miRNA-mRNA interaction. DND1 blocks miRNA interaction with the 3[prime]-untranslated region (3[prime]-UTR) of specific mRNAs and restores protein expression. Previously, we showed that the DNA cytosine deaminase, APOBEC3 (apolipoprotein B mRNA-editing enzyme, catalytic polypeptide like 3), interacts with DND1. APOBEC3 has been primarily studied for its role in restricting and inactivating retroviruses and retroelements. In this report, we examine the significance of DND1-APOBEC3 interaction. We found that while human DND1 inhibits miRNA-mediated inhibition of P27, human APOBEC3G is able to counteract this repression and restore miRNA activity. APOBEC3G, by itself, does not affect the 3[prime]-UTR of P27. We found that APOBEC3G also blocks DND1 function to restore miR-372 and miR-206 inhibition through the 3[prime]-UTRs of LATS2 and CX43, respectively. In corollary experiments, we tested whether DND1 affects the viral restriction function or mutator activity of APOBEC3. We found that DND1 does not affect APOBEC3 inhibition of infectivity of exogenous retrovirus HIV (DeltaVif) or retrotransposition of MusD. In addition, examination of Ter/Ter;Apobec3-/- mice, lead us to conclude that DND1 does not regulate the mutator activity of APOBEC3 in germ cells. In summary, our results show that APOBEC3 is able to modulate DND1 function to regulate miRNA mediated translational regulation in cells but DND1 does not affect known APOBEC3 function.
    Full-text · Article · Jul 2013 · BMC Molecular Biology
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    • "With the env gene of PERV-WZSP [GenBank NO: EF133960] as reference, G to A mutant numbers in the env gene of WZS-PERV(2) represented 52.5% of the total mutant base numbers and G to A mutant numbers in the env gene of WZS-PERV(2) was amounted to 9.42% of the total G base numbers. APOBEC proteins, as members of a family of cytidine deaminases, have the potential to inhibit the replication of a variety of retroviruses including PERV through a cDNA cytosine deamination mechanism [22-25]. We thus presumed that pA3F might contribute to these mutations, so further studies on the exact mechanism were required. "
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    ABSTRACT: Xenotransplantation from animals has been considered to be a preferable approach to alleviate the shortage of human allografts. Pigs are the most suitable candidate because of the anatomical and physiological similarities shared with humans as well as ethical concerns. However, it may be associated with the risk of transmission of infectious porcine pathogens. Porcine endogenous retroviruses (PERVs) are of particular concern because they have been shown to infect human cells in vitro. To date, researches on the molecular characteristics and potential pathogenicity of PERV are still tenuous. In this report, an infectious replication competent clone of PERV from Wuzhishan pigs (WZSPs) in China was generated and characterized. This infectious clone will contribute to studies on PERV virology and control of PERV in xenotransplantation using Chinese miniature pigs. The proviral DNA of PERV from WZSPs was amplified in two overlapping halves. Then the two fragments were isolated, subcloned and fused to generate pBluescriptalphaSK+-WZS-PERV recombinant clones. Screened with RT-PCR, a molecular clone of PERV designated as WZS-PERV(2) was selected. Its infectivity and replication competency were characterized in HEK293 cells by PCR, real-time fluorescent quantitative RT-PCR, western blot, indirect immunofluorescence assay as well as sequence analysis. The ability of WZS-PERV(2) to infect human cells and produce infectious virions were shown after transfection of the clone into HEK293 cells and infection of PERV derived from this recombinant clone. The expression of Gag proteins were detected in HEK293 cells infected with the virus derived from the clone by the indirect immunofluorescence assay and western blot. The results of sequences analysis and comparison combined with the PCR based genotyping result demonstrated that the WZS-PERV(2) belonged to PERV-A subgroup. Compared with a previous proviral DNA clone of PERV (PERV-WZSP), G to A hypermutation occurred in the env gene of WZS-PERV(2) was found, whereas APOBEC proteins have the potential to inhibit the replication of a variety of retroviruses through a cDNA cytosine deamination mechanism, so we presumed these G to A hypermutation might be the contribution of porcine APOBEC3F. Altogether, an infectious replication competent clone of PERV from Chinese miniature pigs (WZSPs) termed WZS-PERV(2) was generated, characterized and sequenced.
    Full-text · Article · Jul 2013 · Virology Journal
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