DEAD/DExH-box RNA helicases catalyze the folding and remodeling of RNA molecules in prokaryotic and eukaryotic cells, as well as in many viruses. They are characterized by the presence of the helicase domain with conserved motifs that are essential for ATP binding and hydrolysis, RNA interaction, and unwinding activities. Large families of DEAD/DExH-box proteins have been described in different organisms, and their role in all molecular processes involving RNA, from transcriptional regulation to mRNA decay, have been described. This review aims to summarize the current knowledge about DEAD/DExH-box proteins in selected protozoan and nematode parasites of medical importance worldwide, such as Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Giardia lamblia, Entamoeba histolytica, and Brugia malayi. We discuss the functional characterization of several proteins in an attempt to understand better the molecular mechanisms involving RNA in these pathogens. The current data also highlight that DEAD/DExH-box RNA helicases might represent feasible drug targets due to their vital role in parasite growth and development.
Animals ; Eukaryota/*enzymology ; *Gene Expression Regulation ; Parasites/*enzymology ; RNA/*metabolism ; RNA Helicases/*metabolism

The zinc-finger antiviral protein (ZAP) is a host factor that specifically inhibits the replication of certain viruses by eliminating viral mRNAs in the cytoplasm. In previous studies, we demonstrated that ZAP directly binds to the viral mRNAs and recruits the RNA exosome to degrade the target RNA. In this article, we provide evidence that a DEXH box RNA helicase, DHX30, is required for optimal antiviral activity of ZAP. Pull-down and co-immunoprecipitation assays demonstrated that DHX30 and ZAP interacted with each other via their N terminal domains. Downregulation of DHX30 with shRNAs reduced ZAP's antiviral activity. These data implicate that DHX30 is a cellular factor involved in the antiviral function of ZAP.
Cytoplasm ; metabolism ; physiology ; DEAD-box RNA Helicases ; metabolism ; Humans ; Immunoprecipitation ; Protein Binding ; physiology ; RNA ; metabolism ; physiology ; RNA Helicases ; metabolism ; physiology ; RNA, Messenger ; metabolism ; physiology ; RNA, Viral ; metabolism ; RNA-Binding Proteins ; metabolism

Pif1 subfamily helicase is conserved from yeast to humans with a lot of cellular functions. In order to elucidate the function of human PIF1 helicase from biochemical level, we cloned human PIF1 gene by PCR from HeLa cell cDNA library. We co-transformed a pMStRNA1 plasmid encoding rare tRNA codons and a plasmid encoding molecular chaperon to greatly enhance the overexpression of human PIF1 protein. Finally we purified full-length PIF1 helicase by column chromatograph carried out at 4 degrees C using fast protein liquid chromatograph (FPLC) system. The human PIF1 protein was purified in enough quantity for detailed biochemical analysis. Biochemical assay showed that PIF1 had ATPase activity and helicase activity. The purification and biochemical properties analysis of human PIF1 helicase will allow us to understand how, at the molecular and mechanistic level, this conserved helicase operates in the cell.
DNA Helicases ; biosynthesis ; genetics ; metabolism ; HeLa Cells ; Humans ; RNA, Transfer ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism

OBJECTIVE: To assess the value of m⁷G-lncRNAs in predicting the prognosis and microenvironment of colorectal cancer (CRC). METHODS: We screened m⁷G-lncRNAs from TCGA to construct an m⁷G-lncRNAs risk model using multivariate Cox analysis, which was validated using ROC and C-index curves. Calibration and nomogram were used to predict the prognosis of CRC patients. Point-bar charts and K-M survival curves were used to assess the correlation of risk scores with the patients' clinical staging and prognosis. CIBERSORT and ESTIMATE were used to explore the association between the tumor microenvironment and immune cell infiltration in patients in high and low risk groups and the correlation of risk scores with microsatellite instability, stem cell index and immune checkpoint expression. A protein-protein interaction network was constructed, and the key targets regulated by m⁷G-lncRNAs were identified and validated in paired samples of CRC and adjacent tissues by immunoblotting. RESULTS: We identified a total of 1722 m⁷G-lncRNAs from TCGA database, from which 12 lncRNAs were screened to construct the risk model. The AUCs of the risk model for predicting survival outcomes at 1, 3 and 5 years were 0.727, 0.747 and 0.794, respectively. The AUC of the nomogram for predicting prognosis was 0.794, and the predicted results were consistent with actual survival outcomes of the patients. The patients in the high-risk group showed more advanced tumor stages and a greater likelihood of high microsatellite instability than those in the low-risk group (P < 0.05). The tumor stemness index was negatively correlated with the risk score (r=-0.19; P=7.3e-05). Patients in the high-risk group had higher stromal cell scores (P=0.0028) and higher total scores (P=0.007) with lowered expressions of activated mast cells (r=-0.11; P=0.045) and resting CD4+ T cells (r=-0.14; P=0.01) and increased expressions of most immune checkpoints (P < 0.05). ATXN2 (P= 0.006) and G3BP1 (P=0.007) were identified as the key targets regulated by m⁷G-lncRNAs, and their expressions were both higher in CRC than in adjacent tissues. CONCLUSION The risk model based on 12 m⁷G-lncRNAs has important prognostic value for CRC and can reflect the microenvironment and the efficacy of immunotherapy in the patients.
Biomarkers, Tumor/metabolism* ; Colonic Neoplasms ; DNA Helicases/metabolism* ; Gene Expression Regulation, Neoplastic ; Humans ; Microsatellite Instability ; Poly-ADP-Ribose Binding Proteins/metabolism* ; Prognosis ; RNA Helicases/metabolism* ; RNA Recognition Motif Proteins/metabolism* ; RNA, Long Noncoding/metabolism* ; Tumor Microenvironment

OBJECTIVETo detect the expression of D-E-A-D-box polypeptide 41 (DDX41) in human dental pulp tissues and cells.

METHODSThe mRNA and protein expressions of DDX41 in human dental pulp cells were detected by RT-PCR and immunocytochemistry, and the expression of DDX41 in human dental pulp tissues was investigated by immunohistochemistry.

RESULTSStrong expressions of DDX41 mRNA and protein were detected in dental pulp cells. In dental pulp tissues, DDX41 was expressed in the cytoplasm and nucleus of odontoblasts.

CONCLUSIONDDX41/STING-dependent TBK1-IRF3-IFN-β signaling pathway may play a role in innate immune responses of the dental pulp to caries and pulpitis.

Cell Nucleus ; metabolism ; Cells, Cultured ; Cytoplasm ; metabolism ; DEAD-box RNA Helicases ; metabolism ; Dental Pulp ; metabolism ; Humans ; Immunohistochemistry ; Odontoblasts ; metabolism ; RNA, Messenger ; Signal Transduction

Up-frameshift 1 (UPF1), as the most critical factor in nonsense-mediated messenger RNA (mRNA) decay (NMD), regulates tumor-associated molecular pathways in many cancers. However, the role of UPF1 in lung adenocarcinoma (LUAD) amino acid metabolism remains largely unknown. In this study, we found that UPF1 was significantly correlated with a portion of amino acid metabolic pathways in LUAD by integrating bioinformatics and metabolomics. We further confirmed that UPF1 knockdown inhibited activating transcription factor 4 (ATF4) and Ser51 phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), the core proteins in amino acid metabolism reprogramming. In addition, UPF1 promotes cell proliferation by increasing the amino-acid levels of LUAD cells, which depends on the function of ATF4. Clinically, UPF1 mRNA expression is abnormal in LUAD tissues, and higher expression of UPF1 and ATF4 was significantly correlated with poor overall survival (OS) in LUAD patients. Our findings reveal that UPF1 is a potential regulator of tumor-associated amino acid metabolism and may be a therapeutic target for LUAD.
Activating Transcription Factor 4/genetics* ; Adenocarcinoma of Lung ; Amino Acids ; Cell Proliferation ; Eukaryotic Initiation Factor-2 ; Humans ; Lung Neoplasms ; RNA Helicases/metabolism* ; RNA, Messenger/metabolism* ; Trans-Activators/metabolism*

A complete proteomics study characterizing active androgen receptor (AR) complexes in prostate cancer (PCa) cells identified a diversity of protein interactors with tumorigenic annotations, including known RNA splicing factors. Thus, we chose to further investigate the functional role of AR-mediated alternative RNA splicing in PCa disease progression. We selected two AR-interacting RNA splicing factors, Src associated in mitosis of 68 kDa (SAM68) and DEAD (Asp-Glu-Ala-Asp) box helicase 5 (DDX5) to examine their associative roles in AR-dependent alternative RNA splicing. To assess the true physiological role of AR in alternative RNA splicing, we assessed splicing profiles of LNCaP PCa cells using exon microarrays and correlated the results to PCa clinical datasets. As a result, we were able to highlight alternative splicing events of clinical significance. Initial use of exon-mini gene cassettes illustrated hormone-dependent AR-mediated exon-inclusion splicing events with SAM68 or exon-exclusion splicing events with DDX5 overexpression. The physiological significance in PCa was investigated through the application of clinical exon array analysis, where we identified exon-gene sets that were able to delineate aggressive disease progression profiles and predict patient disease-free outcomes independently of pathological clinical criteria. Using a clinical dataset with patients categorized as prostate cancer-specific death (PCSD), these exon gene sets further identified a select group of patients with extremely poor disease-free outcomes. Overall, these results strongly suggest a nonclassical role of AR in mediating robust alternative RNA splicing in PCa. Moreover, AR-mediated alternative spicing contributes to aggressive PCa progression, where we identified a new subtype of lethal PCa defined by AR-dependent alternative splicing.
Humans ; Male ; Alternative Splicing ; Cell Line, Tumor ; DEAD-box RNA Helicases/metabolism* ; Disease Progression ; Gene Expression Regulation, Neoplastic ; Prostatic Neoplasms/pathology* ; Receptors, Androgen/metabolism* ; RNA Splicing Factors/metabolism*

Humans ; Carcinogenesis/genetics* ; Gene Expression Regulation, Neoplastic ; Genes, cdc ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/genetics* ; RNA Helicases/metabolism*

Japanese encephalitis virus (JEV) is a single-stranded and positive-sense RNA, which has a single ORF (open reading frame), encoding a polyprotein precursor. Non-structural protein 3 (NS3) plays an important role in processing the polyprotein precursor and has become an important drug target of flavivirus. In this study, NS2BH-NS3 gene was amplified by PCR and subcloned to the prokaryotic expression plasmid, resulting pET30a-NS2BH-NS3. The fusion protein was expressed in Escherichia coli BL21 (DE3) in soluble form after induction by Isopropyl beta-D-1-Thiogalactopyranoside (IPTG). The recombinant protein was purified by Ni-NTA affinity column. Then a fluorescence resonance energy transfer (FRET) method was used to determine enzymatic activity and the assay conditions were optimized. After screening 113 compounds, we found two compounds inhibiting the activity of NS2BH-NS3. This study provides a convenient and cost-effective method for screening of JEV NS3 protease inhibitor.
Encephalitis Virus, Japanese ; enzymology ; Escherichia coli ; metabolism ; High-Throughput Screening Assays ; Protease Inhibitors ; chemistry ; RNA Helicases ; metabolism ; Recombinant Fusion Proteins ; metabolism ; Serine Endopeptidases ; metabolism ; Viral Nonstructural Proteins ; metabolism

Myelodysplastic syndrome (MDS) are a heterogeneous group of hematological malignancies. Currently, in addition to demethylated chemotherapy and hematopoietic stem cell transplantation, MDS patient-derived mesenchymal stem cells (MDS-MSC) play an important role in understanding the pathogenesis of MDS and related therapeutic targets. For example, abnormal expression of DICER1 gene, abnormalities of PI3K/AKT and Wnt/β-catenin signaling pathways provide new therapeutic targets for MDS. In addition, MDS-MSC is also affected by abnormal microenvironment of the body, such as inflammatory factor S100A9, as well as hypercoagulation and iron overload. In this review, genes, signaling pathways, cytokines, hematopoietic microenvironment, and the effect of therapeutic drugs for MDS-MSC were briefly summarized.
Cytokines/metabolism* ; DEAD-box RNA Helicases/metabolism* ; Hematologic Neoplasms/metabolism* ; Humans ; Mesenchymal Stem Cells ; Myelodysplastic Syndromes/genetics* ; Phosphatidylinositol 3-Kinases/metabolism* ; Ribonuclease III/metabolism* ; Tumor Microenvironment