The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response. Recentl...The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response. Recently developed direct-acting antivirals targeting hepatitis C virus (HCV) enzymes reportedly increase the virologic response to therapy but may lead to a selection of drug-resistant variants. Besides direct-acting antivirals, another promising class of HCV drugs in development include host targeting agents that are responsible for interfering with the host factors crucial for the viral life cycle. A family of host proteins known as DEAD-box RNA helicases, characterized by nine conserved motifs, is known to play an important role in RNA metabolism. Several members of this family such as DDX3, DDX5 and DDX6 have been shown to play a role in HCV replication and this review will summarize our current knowledge on their interaction with HCV. As chronic hepatitis C is one of the leading causes of hepatocellular carcinoma, the involvement of DEAD-box RNA helicases in the development of HCC will also be highlighted. Continuing research on the interaction of host DEAD-box proteins with HCV and the contribution to viral replication and pathogenesis could be the panacea for the development of novel therapeutics against HCV.展开更多
RNA helicases,the largest family of proteins that participate in RNA metabolism,stabilize the intracellular environment through various processes,such as translation and pre-RNA splicing.These proteins are also involv...RNA helicases,the largest family of proteins that participate in RNA metabolism,stabilize the intracellular environment through various processes,such as translation and pre-RNA splicing.These proteins are also involved in some diseases,such as cancers and viral diseases.Autophagy,a self-digestive and cytoprotective trafficking process in which superfluous organelles and cellular garbage are degraded to stabilize the internal environment or maintain basic cellular survival,is associated with human diseases.Interestingly,similar to autophagy,RNA helicases play important roles in maintaining cellular homeostasis and are related to many types of diseases.According to recent studies,RNA helicases are closely related to autophagy,participate in regulating autophagy,or serve as a bridge between autophagy and other cellular activities that widely regulate some pathophysiological processes or the development and progress!on of diseases.Here,we summarize the most recent studies to understand how RNA helicases function as regulatory proteins and determine their association with autophagy in various diseases.展开更多
A significant number of mycoviruses have been identified that are related to plant viruses,but their evolutionary relationships are largely unexplored.A fusarivirus,Rhizoctonia solani fusarivirus 4(RsFV4),was identifi...A significant number of mycoviruses have been identified that are related to plant viruses,but their evolutionary relationships are largely unexplored.A fusarivirus,Rhizoctonia solani fusarivirus 4(RsFV4),was identified in phytopathogenic fungus Rhizoctonia solani(R.solani)strain XY74 co-infected by an alphaendornavirus.RsFV4 had a genome of 10,833 nt(excluding the poly-A tail),and consisted of four non-overlapping open reading frames(ORFs).ORF1 encodes an 825 aa protein containing a conserved helicase domain(Hel1).ORF3 encodes 1550 aa protein with two conserved domains,namely an RNA-dependent RNA polymerase(RdRp)and another helicase(Hel2).The ORF2 and ORF4 likely encode two hypothetical proteins(520 and 542 aa)with unknown functions.The phylogenetic analysis based on Hel2 and RdRp suggest that RsFV4 was positioned within the fusarivirus group,but formed an independent branch with three previously reported fusariviruses of R.solani.Notably,the Hel1 and its relatives were phylogenetically closer to helicases of potyviruses and hypoviruses than fusariviruses,suggesting fusarivirus Hel1 formed an evolutionary link between these three virus groups.This finding provides evidence of the occurrence of a horizontal gene transfer or recombination event between mycoviruses and plant viruses or between mycoviruses.Our findings are likely to enhance the understanding of virus evolution and diversity.展开更多
In the era of advancement,the entire world continues to remain baffled by the increased rate of progression of cancer.There has been an unending search for novel thera-peutic targets and prognostic markers to curb the...In the era of advancement,the entire world continues to remain baffled by the increased rate of progression of cancer.There has been an unending search for novel thera-peutic targets and prognostic markers to curb the oncogenic scenario.The DEAD-box RNA he-licases are a large family of proteins characterized by their evolutionary conserved D-E-A-D(Asp-Glu-Ala-Asp)domain and merit consideration in the oncogenic platform.They perform multidimensional functions in RNA metabolism and also in the pathology of cancers.Their bio-logical role ranges from ribosome biogenesis,RNA unwinding,splicing,modification of second-ary and tertiary RNA structures to acting as transcriptional coactivators/repressors of various important oncogenic genes.They also play a crucial role in accelerating oncogenesis by pro-moting cell proliferation and metastasis.DDX5(p68)is one of the archetypal members of this family of proteins and has gained a lot of attention due to its oncogenic attribute.It is found to be overexpressed in major cancer types such as colon,brain,breast,and prostate cancer.It exhibits its multifaceted nature by not only coactivating genes implicated in cancers but also mediating crosstalk across major signaling pathways in cancer.Therefore,in this review,we aim to illustrate a comprehensive overview of DEAD-box RNA helicases especially p68 by focusing on their multifaceted roles in different cancers and the various signaling pathways affected by them.Further,we have also briefly discoursed the therapeutic interventional approaches with the DEAD-box RNA helicases as the pharmacological targets for designing in-hibitors to pave way for cancer therapy.展开更多
Xeroderma pigmentosum group B （XPB） and D （XPD） are two DNA helicases inside the transcription factor TFIIH complex required for both transcription and DNA repair. The importance of these helicases is underscored ...Xeroderma pigmentosum group B （XPB） and D （XPD） are two DNA helicases inside the transcription factor TFIIH complex required for both transcription and DNA repair. The importance of these helicases is underscored by the fact that mutations of XPB and XPD cause diseases with extremely high sensitivity to UV-light and high risk of cancer, premature aging, etc. This mini-review focuses on recent developments in both structural and functional characterization of these XP heficases to illustrate their distinguished biological roles within the architectural restriction of the TFIIH complex. In particular, molecular mechanisms of DNA unwinding by these helicases for promoter opening during transcription initiation and bubble-creation around the lesion during DNA repair are described based on the integration of the crystal structures of XPB and XPD helicases into the architecture of the TFIIH complex.展开更多
Hematopoiesis represents a meticulously regulated and dynamic biological process.Genetic aberrations affecting blood cells,induced by various factors,frequently give rise to hematological tumors.These instances are of...Hematopoiesis represents a meticulously regulated and dynamic biological process.Genetic aberrations affecting blood cells,induced by various factors,frequently give rise to hematological tumors.These instances are often accompanied by a multitude of abnormal post-transcriptional regulatory events,including RNA alternative splicing,RNA localization,RNA degradation,and storage.Notably,post-transcriptional regulation plays a pivotal role in preserving hematopoietic homeostasis.The DEAD-Box RNA helicase genes emerge as crucial post-transcriptional regulatory factors,intricately involved in sustaining normal hematopoiesis through diverse mechanisms such as RNA alternative splicing,RNA modification,and ribosome assembly.This review consolidates the existing knowledge on the role of DEAD-box RNA helicases in regulating normal hematopoiesis and underscores the pathogenicity of mutant DEADBox RNA helicases in malignant hematopoiesis.Emphasis is placed on elucidating both the positive and negative contributions of DEAD-box RNA helicases within the hematopoietic system.展开更多
Structure-based virtual screening utilizing the approved drugs is an intriguing and laudable approach to excavate novel alternatives for different indications based on the vast amount of reported experimental data.Vir...Structure-based virtual screening utilizing the approved drugs is an intriguing and laudable approach to excavate novel alternatives for different indications based on the vast amount of reported experimental data.Virus superfamily 1 helicase could resolve hydrogen bonds between base pairs and participate in nucleic acid replication and has emerged as a potential target for managing virus infection.Nonetheless,current drug exploitation targeting viral helicases is still in infancy.This work establishes an intelligent multi-computational screening programme to screen potential inhibitors targeting tobacco mosaic virus(TMV)helicase using Food and Drug Administration(FDA)-approved commercially available molecule library.The ranked top 6 hits were further validated by root mean square deviations/fluctuations(RMSD/F),molecular mechanics Poisson Boltzmann surface area(MM-PBSA),density functional theory(DFT)calculations,and bioactivity evaluation.Encouragingly,lumacaftor(ΔE_(total)=-29.0kcal/mol,K_(d)=0.22μmol/L,half maximal inhibitory concentration(IC_(50))=162.5μmol/L)displayed superior binding strength and enzyme inhibition against TMV helicase compared to ningnanmycin(K_(d)=9.35μmol/L,IC_(50)>200μmol/L).Therefore,lumacaftor may be able to inhibit TMV replication by binding to helicase and interfering with its biofunctionability.Besides,the lumacaftor-helicase binding mode changes from H-bonding/electrostatic interactions to hydrophobic interactions in trajectory analysis.Overall,current findings suggest this state-of-the-art stratagem is fruitful and has the potential to be engaged in rapid mining of other target inhibitors for disease treatment.展开更多
BACKGROUND Pancreatic cancer(PC)remains one of the most aggressive malignancies,is charac-terized by rapid progression and high metastatic potential,and is the fourth leading cause of cancer-related mortality worldwid...BACKGROUND Pancreatic cancer(PC)remains one of the most aggressive malignancies,is charac-terized by rapid progression and high metastatic potential,and is the fourth leading cause of cancer-related mortality worldwide.The incidence and mortality rates of PC continue to rise annually.Despite advances in imaging technologies and treatment strategies over the past two decades,the 5-year survival rate for patients with PC remains low,at approximately 13%.Patients with advanced PC still experience dismal outcomes,primarily due to the tumor's aggressiveness and high metastatic capacity.Thus,there is an urgent need to identify reliable mole-cular biomarkers and therapeutic targets to improve the prognosis of patients with PC.We comprehensively investigated the expression pattern and functional signi-ficance of DDX10 in PC using a multi-omics integrative approach.We performed bioinformatics analyses of datasets from The Cancer Genome Atlas and Gene Expression Omnibus,tissue microarray-based immunohistochemistry,and a series of in vitro functional assays to assess cellular proliferation,migration,inva-sion,and apoptosis.Additionally,transcriptomic and proteomic analyses were integrated to delineate the molecular regulatory networks that mediate the aggressive phenotype of PC.RESULTS DDX10 was found to be significantly overexpressed at both the mRNA and protein levels in PC tissues compared with adjacent non-tumor tissues.Silencing DDX10 in vitro led to marked inhibition of PC cell proliferation,migration,and invasion,accompanied by enhanced apoptosis.Integrated RNA sequencing,proteomic profiling,and western blot validation revealed that DDX10 modulates key oncogenes including RRM2,LIG1,CDK6,and ITGA2.Notably,ectopic RRM2 overexpression partially rescued the growth-suppressive effects induced by DDX10 knockdown in PANC-1 cells,and high DDX10 expression is associated with poor overall survival in patients with PC.CONCLUSION Collectively,our findings indicate that DDX10 promotes PC cell proliferation primarily by upregulating RRM2,thus highlighting its potential as a promising therapeutic target in PC.展开更多
Background Liver ischemia/reperfusion(I/R)injury is usually caused by hepatic inflow occlusion during liver surgery,and is frequently observed during war wounds and trauma.Hepatocyte ferroptosis plays a critical role ...Background Liver ischemia/reperfusion(I/R)injury is usually caused by hepatic inflow occlusion during liver surgery,and is frequently observed during war wounds and trauma.Hepatocyte ferroptosis plays a critical role in liver I/R injury,however,it remains unclear whether this process is controlled or regulated by members of the DEAD/DExH-box helicase(DDX/DHX)family.Methods The expression of DDX/DHX family members during liver I/R injury was screened using transcriptome analysis.Hepatocyte-specific Dhx58 knockout mice were constructed,and a partial liver I/R operation was performed.Single-cell RNA sequencing(scRNA-seq)in the liver post I/R suggested enhanced ferroptosis by Dhx58hep−/−.The mRNAs and proteins associated with DExH-box helicase 58(DHX58)were screened using RNA immunoprecipitation-sequencing(RIP-seq)and IP-mass spectrometry(IP-MS).Results Excessive production of reactive oxygen species(ROS)decreased the expression of the IFN-stimulated gene Dhx58 in hepatocytes and promoted hepatic ferroptosis,while treatment using IFN-αincreased DHX58 expression and prevented ferroptosis during liver I/R injury.Mechanistically,DHX58 with RNA-binding activity constitutively associates with the mRNA of glutathione peroxidase 4(GPX4),a central ferroptosis suppressor,and recruits the m6A reader YT521-B homology domain containing 2(YTHDC2)to promote the translation of Gpx4 mRNA in an m6A-dependent manner,thus enhancing GPX4 protein levels and preventing hepatic ferroptosis.Conclusions This study provides mechanistic evidence that IFN-αstimulates DHX58 to promote the translation of m6A-modified Gpx4 mRNA,suggesting the potential clinical application of IFN-αin the prevention of hepatic ferroptosis during liver I/R injury.展开更多
The ongoing outbreak of Coronavirus Disease 2019(COVID-19)has become a global public health emergency.SARScoronavirus-2(SARS-CoV-2),the causative pathogen of COVID-19,is a positive-sense single-stranded RNA virus belo...The ongoing outbreak of Coronavirus Disease 2019(COVID-19)has become a global public health emergency.SARScoronavirus-2(SARS-CoV-2),the causative pathogen of COVID-19,is a positive-sense single-stranded RNA virus belonging to the family Coronaviridae.For RNA viruses,virus-encoded RNA helicases have long been recognized to play pivotal roles during viral life cycles by facilitating the correct folding and replication of viral RNAs.Here,our studies show that SARS-CoV-2-encoded nonstructural protein 13(nsp13)possesses the nucleoside triphosphate hydrolase(NTPase)and RNA helicase activities that can hydrolyze all types of NTPs and unwind RNA helices dependently of the presence of NTP,and further characterize the biochemical characteristics of these two enzymatic activities associated with SARS-CoV-2 nsp13.Moreover,we found that some bismuth salts could effectively inhibit both the NTPase and RNA helicase activities of SARS-CoV-2 nsp13 in a dose-dependent manner.Thus,our findings demonstrate the NTPase and helicase activities of SARS-CoV-2 nsp13,which may play an important role in SARS-CoV-2 replication and serve as a target for antivirals.展开更多
Foot-and-mouth disease virus(FMDV)can infect domestic and wild cloven-hoofed animals.The non-structural protein 3D plays an important role in FMDV replication and pathogenesis.However,the interaction partners of 3D,an...Foot-and-mouth disease virus(FMDV)can infect domestic and wild cloven-hoofed animals.The non-structural protein 3D plays an important role in FMDV replication and pathogenesis.However,the interaction partners of 3D,and the effects of those interactions on FMDV replication,remain incompletely elucidated.In the present study,using the yeast two-hybrid system,we identified a porcine cell protein,DEAD-box RNA helicase 1(DDX1),which interacted with FMDV 3D.The DDX1-3D interaction was further confirmed by co-immunoprecipitation experiments and an indirect immunofluorescence assay(IFA)in porcine kidney 15(PK-15)cells.DDX1 was reported to either inhibit or facilitate viral replication and regulate host innate immune responses.However,the roles of DDX1 during FMDV infection remain unclear.Our results revealed that DDX1 inhibited FMDV replication in an ATPase/helicase activity-dependent manner.In addition,DDX1 stimulated IFN-p activation in FMDV-infected cells.Together,our results expand the body of knowledge regarding the role of DDX1 in FMDV infection.展开更多
Recently emerged SARS-CoV-2 caused a major outbreak of coronavirus disease 2019(COVID-19)and instigated a widespread fear,threatening global health safety.To date,no licensed antiviral drugs or vaccines are available ...Recently emerged SARS-CoV-2 caused a major outbreak of coronavirus disease 2019(COVID-19)and instigated a widespread fear,threatening global health safety.To date,no licensed antiviral drugs or vaccines are available against COVID-19 although several clinical trials are under way to test possible therapies.During this urgent situation,computational drug discovery methods provide an alternative to tiresome high-throughput screening,particularly in the hit-to-lead-optimization stage.Identification of small molecules that specifically target viral replication apparatus has indicated the highest potential towards antiviral drug discovery.In this work,we present potential compounds that specifically target SARS-CoV-2 vital proteins,including the main protease,Nsp12 RNA polymerase and Nsp13 helicase.An integrative virtual screening and molecular dynamics simulations approach has facilitated the identification of potential binding modes and favourable molecular interaction profile of corresponding compounds.Moreover,the identification of structurally important binding site residues in conserved motifs located inside the active site highlights relative importance of ligand binding based on residual energy decomposition analysis.Although the current study lacks experimental validation,the structural information obtained from this computational study has paved way for the design of targeted inhibitors to combat COVID-19 outbreak.展开更多
Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most mal...Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most malignant tumors and promotes cancer cell growth.Heat shock protein 90(HSP90)is an important molecular chaperone in the conformational maturation and stabilization of numerous proteins involved in cell growth or survival.Methods:DDX5 m RNA and protein expression in surgically resected HCC tissues from 24 Asian patients were detected by quantitative real-time PCR and Western blot,respectively.The interaction of DDX5-HSP90 was determined by molecular docking,immunoprecipitation,and laser scanning confocal microscopy.The autophagy signal was detected by Western blot.The cell functions and signaling pathways of DDX5 were determined in 2 HCC cell lines.Two different murine HCC xenograft models were used to determine the function of DDX5 and the therapeutic effect of an HSP90 inhibitor.Results:HSP90 interacted directly with DDX5 and inhibited DDX5 protein degradation in the AMPK/ULK1-regulated autophagy pathway.The subsequent accumulation of DDX5 protein induced the malignant phenotype of HCC by activating theβ-catenin signaling pathway.The silencing of DDX5 or treatment with HSP90 inhibitor both blocked in vivo tumor growth in a murine HCC xenograft model.High levels of HSP90 and DDX5 protein were associated with poor prognoses.Conclusions:HSP90 interacted with DDX5 protein and subsequently protected DDX5 protein from AMPK/ULK1-regulated autophagic degradation.DDX5 and HSP90 are therefore potential therapeutic targets for HCC.展开更多
Objective Bloom’s syndrome is an autosomal recessive disorder characterized by genomic instability and a predisposition to many cancers. Mutations of the BLM gene （encoding a BLM helicase） may form a structure of t...Objective Bloom’s syndrome is an autosomal recessive disorder characterized by genomic instability and a predisposition to many cancers. Mutations of the BLM gene （encoding a BLM helicase） may form a structure of the etiology of this disease. As a global pollutant, mercury poses a major threat to human health. The current study was conducted to elucidate the effects of Hg^2＋ on the structure and activity of BLM642‐1290 recombinant helicase, and to further explore the molecular mechanisms of mercury toxicity to the DNA helicase. Methods The effects of Hg^2＋ on biological activity and structure of BLM642‐1290 recombinant helicase were determined by fluorescence polarized, ultraviolet spectroscopic, and free‐phosphorus assay technologies, respectively. Results The helicase activity, the DNA‐binding activity, and the ATPase activity of BLM642‐1290 recombinant helicase were inhibited by Hg^2＋ treatment. The LMCT （ligand‐to‐metal charge transition） peaks of the helicase were enhanced with the increase of the Hg^2＋ level. The LMCT peaks of the same concentration of helicase gradually increased over time. Conclusions The biological activity of BLM642‐1290 recombinant helicase is inhibited by Hg^2＋ treatment. The conformation of the helicase is significantly altered by Hg^2＋ . There exist two binding sites between Hg^2＋ and the helicase, which are located in the amino acid residues 1063‐1066 and 940‐944 of the helicase, respectively.展开更多
The innate immune response is triggered by a variety of pathogens, including viruses, and requires rapid induction of typeⅠ?interferons (IFN), such as IFNβ and IFNα. IFN induction occurs when specific pathogen moti...The innate immune response is triggered by a variety of pathogens, including viruses, and requires rapid induction of typeⅠ?interferons (IFN), such as IFNβ and IFNα. IFN induction occurs when specific pathogen motifs bind to specific cellular receptors. In non-professional immune, virally-infected cells, IFN induction is essentially initiated after the binding of dsRNA structures to TLR3 receptors or to intracytosolic RNA helicases, such as RIG-Ⅰ/MDA5. This leads to the recruitment of specific adaptors, such as TRIF for TLR3 and the mitochondrial-associated IPS-1/VISA/MAVS/CARDIF adapter protein for the RNA helicases, and the ultimate recruitment of kinases, such as MAPKs, the canonical IKK complex and the TBK1/IKKε kinases, which activate the transcription factors ATF-2/ c-jun, NF-κB and IRF3, respectively. The coordinated action of these transcription factors leads to induction of IFN and of pro-inflammatory cytokines and to the establishment of the innate immune response. HCV can cleave both the adapters TRIF and IPS-1/VISA/MAVS/ CARDIF through the action of its NS3/4A protease. This provokes abrogation of the induction of the IFN and cytokine pathways and favours viral propagation and presumably HCV chronic infection.展开更多
基金Supported by Grants from the Ministry of Education of Singapore,Academic Research Fund Tier 1 Grant R-182-000-170-112
文摘The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response. Recently developed direct-acting antivirals targeting hepatitis C virus (HCV) enzymes reportedly increase the virologic response to therapy but may lead to a selection of drug-resistant variants. Besides direct-acting antivirals, another promising class of HCV drugs in development include host targeting agents that are responsible for interfering with the host factors crucial for the viral life cycle. A family of host proteins known as DEAD-box RNA helicases, characterized by nine conserved motifs, is known to play an important role in RNA metabolism. Several members of this family such as DDX3, DDX5 and DDX6 have been shown to play a role in HCV replication and this review will summarize our current knowledge on their interaction with HCV. As chronic hepatitis C is one of the leading causes of hepatocellular carcinoma, the involvement of DEAD-box RNA helicases in the development of HCC will also be highlighted. Continuing research on the interaction of host DEAD-box proteins with HCV and the contribution to viral replication and pathogenesis could be the panacea for the development of novel therapeutics against HCV.
基金State S&T Project of 13th Five Year of China(No.2018ZX10302206)the National Basic Research Program(973)of China(No.2017YFA0503402)the Independent Project Fund of the State Key Laboratory for Diagnosis and Treatment of Infectious Disease,Hangzhou,China。
文摘RNA helicases,the largest family of proteins that participate in RNA metabolism,stabilize the intracellular environment through various processes,such as translation and pre-RNA splicing.These proteins are also involved in some diseases,such as cancers and viral diseases.Autophagy,a self-digestive and cytoprotective trafficking process in which superfluous organelles and cellular garbage are degraded to stabilize the internal environment or maintain basic cellular survival,is associated with human diseases.Interestingly,similar to autophagy,RNA helicases play important roles in maintaining cellular homeostasis and are related to many types of diseases.According to recent studies,RNA helicases are closely related to autophagy,participate in regulating autophagy,or serve as a bridge between autophagy and other cellular activities that widely regulate some pathophysiological processes or the development and progress!on of diseases.Here,we summarize the most recent studies to understand how RNA helicases function as regulatory proteins and determine their association with autophagy in various diseases.
基金financially supported by the Fundamental Research Funds for the Central Universities(2662018PY041)the Natural Science Foundation of China(31772111)the National Key Research and Development Program of China(2017YFD0201100)。
文摘A significant number of mycoviruses have been identified that are related to plant viruses,but their evolutionary relationships are largely unexplored.A fusarivirus,Rhizoctonia solani fusarivirus 4(RsFV4),was identified in phytopathogenic fungus Rhizoctonia solani(R.solani)strain XY74 co-infected by an alphaendornavirus.RsFV4 had a genome of 10,833 nt(excluding the poly-A tail),and consisted of four non-overlapping open reading frames(ORFs).ORF1 encodes an 825 aa protein containing a conserved helicase domain(Hel1).ORF3 encodes 1550 aa protein with two conserved domains,namely an RNA-dependent RNA polymerase(RdRp)and another helicase(Hel2).The ORF2 and ORF4 likely encode two hypothetical proteins(520 and 542 aa)with unknown functions.The phylogenetic analysis based on Hel2 and RdRp suggest that RsFV4 was positioned within the fusarivirus group,but formed an independent branch with three previously reported fusariviruses of R.solani.Notably,the Hel1 and its relatives were phylogenetically closer to helicases of potyviruses and hypoviruses than fusariviruses,suggesting fusarivirus Hel1 formed an evolutionary link between these three virus groups.This finding provides evidence of the occurrence of a horizontal gene transfer or recombination event between mycoviruses and plant viruses or between mycoviruses.Our findings are likely to enhance the understanding of virus evolution and diversity.
基金supported by the Department of Science and Technology(Nano Mission:DST/NM/NT/2018/105(G),SERB:EMR/2017/000992/HS&EMR/2017/001183),CSIR(FBR Project#31-2(274)2020-21),Govt.of India.
文摘In the era of advancement,the entire world continues to remain baffled by the increased rate of progression of cancer.There has been an unending search for novel thera-peutic targets and prognostic markers to curb the oncogenic scenario.The DEAD-box RNA he-licases are a large family of proteins characterized by their evolutionary conserved D-E-A-D(Asp-Glu-Ala-Asp)domain and merit consideration in the oncogenic platform.They perform multidimensional functions in RNA metabolism and also in the pathology of cancers.Their bio-logical role ranges from ribosome biogenesis,RNA unwinding,splicing,modification of second-ary and tertiary RNA structures to acting as transcriptional coactivators/repressors of various important oncogenic genes.They also play a crucial role in accelerating oncogenesis by pro-moting cell proliferation and metastasis.DDX5(p68)is one of the archetypal members of this family of proteins and has gained a lot of attention due to its oncogenic attribute.It is found to be overexpressed in major cancer types such as colon,brain,breast,and prostate cancer.It exhibits its multifaceted nature by not only coactivating genes implicated in cancers but also mediating crosstalk across major signaling pathways in cancer.Therefore,in this review,we aim to illustrate a comprehensive overview of DEAD-box RNA helicases especially p68 by focusing on their multifaceted roles in different cancers and the various signaling pathways affected by them.Further,we have also briefly discoursed the therapeutic interventional approaches with the DEAD-box RNA helicases as the pharmacological targets for designing in-hibitors to pave way for cancer therapy.
文摘Xeroderma pigmentosum group B （XPB） and D （XPD） are two DNA helicases inside the transcription factor TFIIH complex required for both transcription and DNA repair. The importance of these helicases is underscored by the fact that mutations of XPB and XPD cause diseases with extremely high sensitivity to UV-light and high risk of cancer, premature aging, etc. This mini-review focuses on recent developments in both structural and functional characterization of these XP heficases to illustrate their distinguished biological roles within the architectural restriction of the TFIIH complex. In particular, molecular mechanisms of DNA unwinding by these helicases for promoter opening during transcription initiation and bubble-creation around the lesion during DNA repair are described based on the integration of the crystal structures of XPB and XPD helicases into the architecture of the TFIIH complex.
基金Chongqing Science Fund for Distinguished Young Scholars(No.CSTB2022NSCQJQX0032)Chongqing University Innovation Research Group Project(No.CXQT21011)+2 种基金Chongqing Medical University Youth Innovation in Future Medicine(No.W0156)the National Natural Science Foundation of China(No.82200123)Natural Science Foundation of Chongqing,China,(No.CSTB2023NSCQ-MSX0280).
文摘Hematopoiesis represents a meticulously regulated and dynamic biological process.Genetic aberrations affecting blood cells,induced by various factors,frequently give rise to hematological tumors.These instances are often accompanied by a multitude of abnormal post-transcriptional regulatory events,including RNA alternative splicing,RNA localization,RNA degradation,and storage.Notably,post-transcriptional regulation plays a pivotal role in preserving hematopoietic homeostasis.The DEAD-Box RNA helicase genes emerge as crucial post-transcriptional regulatory factors,intricately involved in sustaining normal hematopoiesis through diverse mechanisms such as RNA alternative splicing,RNA modification,and ribosome assembly.This review consolidates the existing knowledge on the role of DEAD-box RNA helicases in regulating normal hematopoiesis and underscores the pathogenicity of mutant DEADBox RNA helicases in malignant hematopoiesis.Emphasis is placed on elucidating both the positive and negative contributions of DEAD-box RNA helicases within the hematopoietic system.
基金financially supported by National Natural Science Foundation of China(Nos.32372610,U23A20201,32160661,32202359)National Key Research and Development Program of China(No.2022YFD1700300)the Central Government Guides Local Science and Technology Development Fund Projects(Nos.[Qiankehezhongyindi(2023)001]and[Qiankehezhongyindi[2024]007])。
文摘Structure-based virtual screening utilizing the approved drugs is an intriguing and laudable approach to excavate novel alternatives for different indications based on the vast amount of reported experimental data.Virus superfamily 1 helicase could resolve hydrogen bonds between base pairs and participate in nucleic acid replication and has emerged as a potential target for managing virus infection.Nonetheless,current drug exploitation targeting viral helicases is still in infancy.This work establishes an intelligent multi-computational screening programme to screen potential inhibitors targeting tobacco mosaic virus(TMV)helicase using Food and Drug Administration(FDA)-approved commercially available molecule library.The ranked top 6 hits were further validated by root mean square deviations/fluctuations(RMSD/F),molecular mechanics Poisson Boltzmann surface area(MM-PBSA),density functional theory(DFT)calculations,and bioactivity evaluation.Encouragingly,lumacaftor(ΔE_(total)=-29.0kcal/mol,K_(d)=0.22μmol/L,half maximal inhibitory concentration(IC_(50))=162.5μmol/L)displayed superior binding strength and enzyme inhibition against TMV helicase compared to ningnanmycin(K_(d)=9.35μmol/L,IC_(50)>200μmol/L).Therefore,lumacaftor may be able to inhibit TMV replication by binding to helicase and interfering with its biofunctionability.Besides,the lumacaftor-helicase binding mode changes from H-bonding/electrostatic interactions to hydrophobic interactions in trajectory analysis.Overall,current findings suggest this state-of-the-art stratagem is fruitful and has the potential to be engaged in rapid mining of other target inhibitors for disease treatment.
基金Supported by National Natural Science Foundation of China,No.82160588Health Commission of Gansu Province,No.GSWSKY2021-032+1 种基金Natural Science Foundation of Gansu Province,No.24JRRA585Gansu Provincial Hospital Science and Technology Innovation Platform Fund Project,No.21GSSYB-23.
文摘BACKGROUND Pancreatic cancer(PC)remains one of the most aggressive malignancies,is charac-terized by rapid progression and high metastatic potential,and is the fourth leading cause of cancer-related mortality worldwide.The incidence and mortality rates of PC continue to rise annually.Despite advances in imaging technologies and treatment strategies over the past two decades,the 5-year survival rate for patients with PC remains low,at approximately 13%.Patients with advanced PC still experience dismal outcomes,primarily due to the tumor's aggressiveness and high metastatic capacity.Thus,there is an urgent need to identify reliable mole-cular biomarkers and therapeutic targets to improve the prognosis of patients with PC.We comprehensively investigated the expression pattern and functional signi-ficance of DDX10 in PC using a multi-omics integrative approach.We performed bioinformatics analyses of datasets from The Cancer Genome Atlas and Gene Expression Omnibus,tissue microarray-based immunohistochemistry,and a series of in vitro functional assays to assess cellular proliferation,migration,inva-sion,and apoptosis.Additionally,transcriptomic and proteomic analyses were integrated to delineate the molecular regulatory networks that mediate the aggressive phenotype of PC.RESULTS DDX10 was found to be significantly overexpressed at both the mRNA and protein levels in PC tissues compared with adjacent non-tumor tissues.Silencing DDX10 in vitro led to marked inhibition of PC cell proliferation,migration,and invasion,accompanied by enhanced apoptosis.Integrated RNA sequencing,proteomic profiling,and western blot validation revealed that DDX10 modulates key oncogenes including RRM2,LIG1,CDK6,and ITGA2.Notably,ectopic RRM2 overexpression partially rescued the growth-suppressive effects induced by DDX10 knockdown in PANC-1 cells,and high DDX10 expression is associated with poor overall survival in patients with PC.CONCLUSION Collectively,our findings indicate that DDX10 promotes PC cell proliferation primarily by upregulating RRM2,thus highlighting its potential as a promising therapeutic target in PC.
基金National Key Research and Development Program of China(2023YFC2505900)National Natural Science Foundation of China(92269204,82171755,92369106,82171749,82171811,82073184)+1 种基金Military Outstanding Youth Program(2020QN06119,01-SWK JYCJJ07,23SWAQ53)Program of Leading Talents in Shanghai,and Shanghai Shuguang Program(20SG39)。
文摘Background Liver ischemia/reperfusion(I/R)injury is usually caused by hepatic inflow occlusion during liver surgery,and is frequently observed during war wounds and trauma.Hepatocyte ferroptosis plays a critical role in liver I/R injury,however,it remains unclear whether this process is controlled or regulated by members of the DEAD/DExH-box helicase(DDX/DHX)family.Methods The expression of DDX/DHX family members during liver I/R injury was screened using transcriptome analysis.Hepatocyte-specific Dhx58 knockout mice were constructed,and a partial liver I/R operation was performed.Single-cell RNA sequencing(scRNA-seq)in the liver post I/R suggested enhanced ferroptosis by Dhx58hep−/−.The mRNAs and proteins associated with DExH-box helicase 58(DHX58)were screened using RNA immunoprecipitation-sequencing(RIP-seq)and IP-mass spectrometry(IP-MS).Results Excessive production of reactive oxygen species(ROS)decreased the expression of the IFN-stimulated gene Dhx58 in hepatocytes and promoted hepatic ferroptosis,while treatment using IFN-αincreased DHX58 expression and prevented ferroptosis during liver I/R injury.Mechanistically,DHX58 with RNA-binding activity constitutively associates with the mRNA of glutathione peroxidase 4(GPX4),a central ferroptosis suppressor,and recruits the m6A reader YT521-B homology domain containing 2(YTHDC2)to promote the translation of Gpx4 mRNA in an m6A-dependent manner,thus enhancing GPX4 protein levels and preventing hepatic ferroptosis.Conclusions This study provides mechanistic evidence that IFN-αstimulates DHX58 to promote the translation of m6A-modified Gpx4 mRNA,suggesting the potential clinical application of IFN-αin the prevention of hepatic ferroptosis during liver I/R injury.
基金supported by the Strategic Priority Research Program of CAS(XDB29010300 to X.Z.)National Natural Science Foundation of China(81873964 to Y.Q.,31800140 to J.M.and 31670161 to X.Z.)+1 种基金National Science and Technology Major Project(2018ZX10101004 to X.Z.)the Science and Technology Development Fund,Macao SAR(0007/2020/A to R.W)。
文摘The ongoing outbreak of Coronavirus Disease 2019(COVID-19)has become a global public health emergency.SARScoronavirus-2(SARS-CoV-2),the causative pathogen of COVID-19,is a positive-sense single-stranded RNA virus belonging to the family Coronaviridae.For RNA viruses,virus-encoded RNA helicases have long been recognized to play pivotal roles during viral life cycles by facilitating the correct folding and replication of viral RNAs.Here,our studies show that SARS-CoV-2-encoded nonstructural protein 13(nsp13)possesses the nucleoside triphosphate hydrolase(NTPase)and RNA helicase activities that can hydrolyze all types of NTPs and unwind RNA helices dependently of the presence of NTP,and further characterize the biochemical characteristics of these two enzymatic activities associated with SARS-CoV-2 nsp13.Moreover,we found that some bismuth salts could effectively inhibit both the NTPase and RNA helicase activities of SARS-CoV-2 nsp13 in a dose-dependent manner.Thus,our findings demonstrate the NTPase and helicase activities of SARS-CoV-2 nsp13,which may play an important role in SARS-CoV-2 replication and serve as a target for antivirals.
基金supported by grants from the National Natural Science Foundation of China (Nos. 31302106, 31260616, and 31602035)the National Key Research and Development Program of China (Nos. 2016YFD0500901 and 2017YFD0500903)
文摘Foot-and-mouth disease virus(FMDV)can infect domestic and wild cloven-hoofed animals.The non-structural protein 3D plays an important role in FMDV replication and pathogenesis.However,the interaction partners of 3D,and the effects of those interactions on FMDV replication,remain incompletely elucidated.In the present study,using the yeast two-hybrid system,we identified a porcine cell protein,DEAD-box RNA helicase 1(DDX1),which interacted with FMDV 3D.The DDX1-3D interaction was further confirmed by co-immunoprecipitation experiments and an indirect immunofluorescence assay(IFA)in porcine kidney 15(PK-15)cells.DDX1 was reported to either inhibit or facilitate viral replication and regulate host innate immune responses.However,the roles of DDX1 during FMDV infection remain unclear.Our results revealed that DDX1 inhibited FMDV replication in an ATPase/helicase activity-dependent manner.In addition,DDX1 stimulated IFN-p activation in FMDV-infected cells.Together,our results expand the body of knowledge regarding the role of DDX1 in FMDV infection.
基金This study was supported by IRO scholarship Ph.D.Grant.
文摘Recently emerged SARS-CoV-2 caused a major outbreak of coronavirus disease 2019(COVID-19)and instigated a widespread fear,threatening global health safety.To date,no licensed antiviral drugs or vaccines are available against COVID-19 although several clinical trials are under way to test possible therapies.During this urgent situation,computational drug discovery methods provide an alternative to tiresome high-throughput screening,particularly in the hit-to-lead-optimization stage.Identification of small molecules that specifically target viral replication apparatus has indicated the highest potential towards antiviral drug discovery.In this work,we present potential compounds that specifically target SARS-CoV-2 vital proteins,including the main protease,Nsp12 RNA polymerase and Nsp13 helicase.An integrative virtual screening and molecular dynamics simulations approach has facilitated the identification of potential binding modes and favourable molecular interaction profile of corresponding compounds.Moreover,the identification of structurally important binding site residues in conserved motifs located inside the active site highlights relative importance of ligand binding based on residual energy decomposition analysis.Although the current study lacks experimental validation,the structural information obtained from this computational study has paved way for the design of targeted inhibitors to combat COVID-19 outbreak.
基金funding support from the National Natural Science Foundation of China(Grant Nos.81672467,81702773,81702389,and 81672368)the Major National R&D Project(Grant Nos.2018ZX10723204,2018ZX10302205,and 2018ZX09J18107)the Natural Science Foundation of Beijing(Grant No.7172207)。
文摘Objective:Hepatocellular carcinoma(HCC),the main type of liver cancer,has a high morbidity and mortality,and a poor prognosis.RNA helicase DDX5,which acts as a transcriptional co-regulator,is overexpressed in most malignant tumors and promotes cancer cell growth.Heat shock protein 90(HSP90)is an important molecular chaperone in the conformational maturation and stabilization of numerous proteins involved in cell growth or survival.Methods:DDX5 m RNA and protein expression in surgically resected HCC tissues from 24 Asian patients were detected by quantitative real-time PCR and Western blot,respectively.The interaction of DDX5-HSP90 was determined by molecular docking,immunoprecipitation,and laser scanning confocal microscopy.The autophagy signal was detected by Western blot.The cell functions and signaling pathways of DDX5 were determined in 2 HCC cell lines.Two different murine HCC xenograft models were used to determine the function of DDX5 and the therapeutic effect of an HSP90 inhibitor.Results:HSP90 interacted directly with DDX5 and inhibited DDX5 protein degradation in the AMPK/ULK1-regulated autophagy pathway.The subsequent accumulation of DDX5 protein induced the malignant phenotype of HCC by activating theβ-catenin signaling pathway.The silencing of DDX5 or treatment with HSP90 inhibitor both blocked in vivo tumor growth in a murine HCC xenograft model.High levels of HSP90 and DDX5 protein were associated with poor prognoses.Conclusions:HSP90 interacted with DDX5 protein and subsequently protected DDX5 protein from AMPK/ULK1-regulated autophagic degradation.DDX5 and HSP90 are therefore potential therapeutic targets for HCC.
基金supported by the Natural Sciences Foundation of China (NSFC, No.30660043)the National Basic Research Program of China (2010CB534912)+1 种基金the Doctoral Program of the Ministry of Education of China (No.200806570003)the Governor Talents Foundation of Guizhou Province (No.200822)
文摘Objective Bloom’s syndrome is an autosomal recessive disorder characterized by genomic instability and a predisposition to many cancers. Mutations of the BLM gene （encoding a BLM helicase） may form a structure of the etiology of this disease. As a global pollutant, mercury poses a major threat to human health. The current study was conducted to elucidate the effects of Hg^2＋ on the structure and activity of BLM642‐1290 recombinant helicase, and to further explore the molecular mechanisms of mercury toxicity to the DNA helicase. Methods The effects of Hg^2＋ on biological activity and structure of BLM642‐1290 recombinant helicase were determined by fluorescence polarized, ultraviolet spectroscopic, and free‐phosphorus assay technologies, respectively. Results The helicase activity, the DNA‐binding activity, and the ATPase activity of BLM642‐1290 recombinant helicase were inhibited by Hg^2＋ treatment. The LMCT （ligand‐to‐metal charge transition） peaks of the helicase were enhanced with the increase of the Hg^2＋ level. The LMCT peaks of the same concentration of helicase gradually increased over time. Conclusions The biological activity of BLM642‐1290 recombinant helicase is inhibited by Hg^2＋ treatment. The conformation of the helicase is significantly altered by Hg^2＋ . There exist two binding sites between Hg^2＋ and the helicase, which are located in the amino acid residues 1063‐1066 and 940‐944 of the helicase, respectively.
基金grants from the Agence Nationale pour la Recherche contre le SIDA
文摘The innate immune response is triggered by a variety of pathogens, including viruses, and requires rapid induction of typeⅠ?interferons (IFN), such as IFNβ and IFNα. IFN induction occurs when specific pathogen motifs bind to specific cellular receptors. In non-professional immune, virally-infected cells, IFN induction is essentially initiated after the binding of dsRNA structures to TLR3 receptors or to intracytosolic RNA helicases, such as RIG-Ⅰ/MDA5. This leads to the recruitment of specific adaptors, such as TRIF for TLR3 and the mitochondrial-associated IPS-1/VISA/MAVS/CARDIF adapter protein for the RNA helicases, and the ultimate recruitment of kinases, such as MAPKs, the canonical IKK complex and the TBK1/IKKε kinases, which activate the transcription factors ATF-2/ c-jun, NF-κB and IRF3, respectively. The coordinated action of these transcription factors leads to induction of IFN and of pro-inflammatory cytokines and to the establishment of the innate immune response. HCV can cleave both the adapters TRIF and IPS-1/VISA/MAVS/ CARDIF through the action of its NS3/4A protease. This provokes abrogation of the induction of the IFN and cytokine pathways and favours viral propagation and presumably HCV chronic infection.
