DEAD-box RNA helicase DDX3 connects CRM1-dependent nuclear export and translation of the HIV-1 unspliced mRNA through its N-terminal domain

Fröhlich, Alvaro; Rojas-Araya, Bárbara; Pereira-Montecinos, Camila; Dellarossa, Alessandra; Toro-Ascuy, Daniela; Prades-Pérez, Yara; García-de-Gracia, Francisco; Garcés-Alday, Andrea; Rubilar, Paulina S.; Valiente-Echeverría, Fernando; Ohlmann, Théophile; Soto-Rifo, Ricardo

doi:10.1016/j.bbagrm.2016.03.009

Cited by 49 publications

(49 citation statements)

References 42 publications

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“…Our analysis of DDX3 deletion mutants showed that deletion of both areas resulted in an increase in nuclear DDX3, but only the construct that lacked the NES lost its sensitivity to CRM1 inhibition, indicating that this is the essential domain for CRM1-mediated export. A similar conclusion was recently made by Fröhlich et al, who found the N-terminal to be essential for DDX3 transportation out of the nucleus into cytoplasmic unspliced HIV-1 mRNA ribonucleoprotein complexes 50. It is possible that the 260–517 region of DDX3 is necessary for binding other exporters of DDX3 like TAP 5…”

Section: Discussionsupporting

confidence: 74%

Nuclear DDX3 expression predicts poor outcome in colorectal and breast cancer

Voss¹,

Vesuna²,

Bol³

et al. 2017

OTT

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PurposeDEAD box protein 3 (DDX3) is an RNA helicase with oncogenic properties that shuttles between the cytoplasm and nucleus. The majority of DDX3 is found in the cytoplasm, but a subset of tumors has distinct nuclear DDX3 localization of yet unknown biological significance. This study aimed to evaluate the significance of and mechanisms behind nuclear DDX3 expression in colorectal and breast cancer.MethodsExpression of nuclear DDX3 and the nuclear exporter chromosome region maintenance 1 (CRM1) was evaluated by immunohistochemistry in 304 colorectal and 292 breast cancer patient samples. Correlations between the subcellular localization of DDX3 and CRM1 and the difference in overall survival between patients with and without nuclear DDX3 were studied. In addition, DDX3 mutants were created for in vitro evaluation of the mechanism behind nuclear retention of DDX3.ResultsDDX3 was present in the nucleus of 35% of colorectal and 48% of breast cancer patient samples and was particularly strong in the nucleolus. Nuclear DDX3 correlated with worse overall survival in both colorectal (hazard ratio [HR] 2.34, P<0.001) and breast cancer (HR 2.39, P=0.004) patients. Colorectal cancers with nuclear DDX3 expression more often had cytoplasmic expression of the nuclear exporter CRM1 (relative risk 1.67, P=0.04). In vitro analysis of DDX3 deletion mutants demonstrated that CRM1-mediated export was most dependent on the N-terminal nuclear export signal.ConclusionOverall, we conclude that nuclear DDX3 is partially CRM1-mediated and predicts worse survival in colorectal and breast cancer patients, putting it forward as a target for therapeutic intervention with DDX3 inhibitors under development in these cancer types.

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Section: Discussionsupporting

confidence: 74%

Nuclear DDX3 expression predicts poor outcome in colorectal and breast cancer

Voss¹,

Vesuna²,

Bol³

et al. 2017

OTT

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“…The pNL4.3-ΔEnv, pNL4.3R, pNL4.3R-ΔRev, pROD10R and pNCAC proviral vectors were previously described (18,29,30). The pcDNA3-Flag-CTIF, pcDNA3-Flag-CTIF(1-305) and pcDNA3-Flag-CTIF(306-598) were previously described (25).…”

Section: Methodsmentioning

confidence: 99%

“…The pcDNA3-Flag-CTIF, pcDNA3-Flag-CTIF(1-305) and pcDNA3-Flag-CTIF(306-598) were previously described (25). The pcDNA-d2EGFP, pCDNA β-globin 5’-UTR, pCIneo-Renilla and pEGFP-Rev were previously described (18,29).…”

Section: Methodsmentioning

confidence: 99%

CBP80/20-dependent translation initiation factor (CTIF) inhibits HIV-1 Gag synthesis by targeting the function of the viral protein Rev

García-de-Gracia

Toro-Ascuy

Riquelme-Barrios

et al. 2019

Preprint

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1Translation initiation of the human immunodeficiency virus type-1 (HIV-1) unspliced mRNA 2 has been shown to occur through cap-dependent and IRES-driven mechanisms. Previous studies 3 suggested that the nuclear cap-binding complex (CBC) rather than eIF4E drives cap-dependent 4 translation of the unspliced mRNA and we have recently reported that the CBC subunit CBP80 5 supports the function of the viral protein Rev during nuclear export and translation of this viral 6 transcript. Ribosome recruitment during CBC-dependent translation of cellular mRNAs relies on 7 the activity CBP80/20 translation initiation factor (CTIF), which bridges CBP80 and the 40S 8 ribosomal subunit through interactions with eIF3g. Here, we report that CTIF restricts HIV-1 9 replication by interfering with Gag synthesis from the unspliced mRNA. Our results indicate that 10 CTIF associates with Rev through its N-terminal domain and is recruited onto the unspliced 11 mRNA ribonucleoprotein complex in order to block translation. We also demonstrate that CTIF 12 induces the cytoplasmic accumulation of Rev impeding the association of the viral protein with 13 CBP80. We finally show that CTIF restricts HIV-2 but not MLV Gag synthesis indicating an 14 inhibitory mechanism conserved in Rev-expressing human lentiviruses. 15 16 17 18 19 20

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“…[47] THF cells [52] hepatitis C [54À57] HIV-1 [55,58,59] norovirus, West Nile virus, Japanese encephalitis virus [55] MAVS À DDX3 can activate MAVS and act as a scaffolding adaptor in downstream signaling TRAF3 [46] À Interaction between DDX3 and TRAF3 triggers K63-linked polyubiquitination and oligomerization of TRAF3 IKKε [45,46] À IKKε and DDX3 phosphorylate each other to promote downstream signaling in the MAVS pathway TBK1 [47] À DDX3 undergoes phosphorylation by TBK1 before it can act as a transcription factor for IFN-β PP2A [48] À Positive regulation of NF-κB transcriptional activity by modulation of PP2A activity NF-κB subunit p65 [49] À Suppression of NF-κB transcriptional activity eIF4E and PABP1 [50] À Promotion of stress granule formation and inhibition of translation Sensor of bacterial and viral RNA, activates the NLRP3 inflammasome in macrophages. [85,86].…”

Section: Raw2647 Macrophagesmentioning

confidence: 99%

“…Similarly, HIV-1 interrupts MAVS signaling as viral feedback to the initial sensing of HIV-1 RNA by DDX3 [58]. At the same time, HIV-1 utilizes the CRM1/ DDX3 complex in nucleus for the Rev-dependent nuclear export of viral RNAs, or DDX3 itself to promote the translation of the HIV-1 unspliced mRNA [59].…”

Section: Ddx3mentioning

confidence: 99%