Table 2 |
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Retrovirus:host interactions involved in retroviral translation control |
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Host factor |
Examples of interacting virusa |
Effect on translation |
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Interacts with retrovirus protein & RNA |
Protein kinase R (PKR) |
HIV-1, HTLV-1 |
HIV-1 Tat reduces PKR autophosphorylation. Tat and eIF2α compete as substrates of PKR. High levels of HIV-1 TAR RNA or HTLV-1 RxRE inhibit PKR autophosphorylation. |
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Small RNA pathway components (Dicer & Drosha) |
PFV, HIV-1 |
PFV Tas and HIV-1 Tat act as RNA silencing suppressors that combat the antiviral effect of small RNA pathway. Also miRNAs may be encoded by retroviruses that downregulate host antiviral defense. |
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Interacts with retrovirus RNA |
TAR RNA binding protein (TRBP) |
HIV-1 |
Binding of TRBP to HIV-1 TAR RNA results in increased HIV-1 transcription and translation. |
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2', 5'-oligoadenylate-synthetase/RNaseL |
HIV-1, HTLV-1 |
HIV-1 5' UTR RNA binds 2-5OAS resulting in RNAseL activity in vitro. HIV-1 infection is associated with reduced interferon production and reduced 2-5A:RNAseL binding, allowing HIV-1 mRNA to evade cleavage by RNaseL. HTLV-1 RxRE activates 2-5OAS in vitro. |
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RNA helicase A (RHA or DHX9) |
SNV, REV-A, HTLV-1, MPMV, HFV, FeLV, BLV, HIV-1 |
RHA binds PCE mRNA leading to increased polysome association and efficient protein synthesis. |
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9G8 |
MPMV |
In overexpression experiments, hyper-phosphorylated 9G8 binds constitutive transport element-containing reporter mRNA resulting in increased polysome accumulation and protein synthesis. |
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Sam68, SLM-1, SLM-2 |
HIV-1, HTLV-1, EIAV, MPMV |
Sam68, SLM-1 and SLM-2 act synergistically with HIV-1 Rev, HTLV-1 Rex and EIAV ERev to facilitate expression and proper cytoplasmic localization of RRE-containing mRNA. Sam68 also enhances translation of mRNA containing the MPMV constitutive transport element. |
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hnRNP E1 |
HIV-1 |
hnRNPE1 binds HIV-1 mRNA at the exon splicing silencer in Rev exon (ESSE) and reduces Gag, Env, and Rev protein production. |
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eRF1 |
MLV |
MLV reverse transcriptase binds eRF1 promoting readthrough of the gag termination codon to produce proteins encoded by gag-pol. |
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a BLV, bovine leukemia virus; EIAV, equine infectious anemia virus; FeLV, feline leukemia virus; HFV, human foamy virus; HTLV-1, human T-cell leukemia virus type 1; MLV, murine leukemia virus; MPMV, Mason-Pfizer monkey virus; REV-A, reticuloendotheliosis virus strain A; SNV, spleen necrosis virus. |
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Bolinger and Boris-Lawrie Retrovirology 2009 6:8 doi:10.1186/1742-4690-6-8 |
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