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
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
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
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
This investigation aimed to unveil new prospective diagnosis-related biomarkers together with treatment targets against glioblastoma.Methods:The expression levels of long non-coding RNA(lncRNA)DPP10-AS1 were assessed ...This investigation aimed to unveil new prospective diagnosis-related biomarkers together with treatment targets against glioblastoma.Methods:The expression levels of long non-coding RNA(lncRNA)DPP10-AS1 were assessed using real-time quantitative polymerase chain reaction(RT-qPCR)within both the patient tissue specimens and glioblastoma cell lines.The relationship between lncRNA DPP10-AS1 expression in glioblastoma and patient prognosis was investigated.Cell Counting Kit-8(CCK-8),transwell,and clonogenic experiments were utilized to assess tumor cells’proliferation,invasiveness,and migratory potentials after lncRNA DPP10-AS1 expression was up or down-regulated.Using an online bioinformatics prediction tool,the intracellular localization of lncRNA DPP10-AS1 and its target miRNA were predicted,and RNA-FISH verified results.A dual-luciferase reporter experiment validated the relationship across miR-24-3p together with lncRNA DPP10-AS1.MiR-24-3p expression within glioblastoma was identified through RT-qPCR,and potential link across miR-24-3p and lncRNA DPP10-AS1 was assessed using Pearson correlation analysis.Moreover,influence from lncRNA DPP10-AS1/miR-24-3p axis upon glioblastoma cell progression was assessed in vivo via a subcutaneous xenograft tumor model.Results:The expression of lncRNA DPP10-AS1 was notably reduced in both surgical specimens of glioblastoma and the equivalent cell lines.Low level of lncRNA DPP10-AS1 in glioblastoma is following poor prognosis.The downregulation of lncRNA DPP10-AS1 in glioblastoma cells resulted in enhanced cellular proliferation,migration,and invasion capabilities,accompanied by downregulated E-cadherin and upregulated vimentin and N-cadherin.Additionally,the observed upregulation of lncRNA DPP10-AS1 demonstrated a substantial inhibitory function upon proliferation,invasion,and migratory capabilities of LN229 cells.Subcellular localization disclosed that lncRNA DPP10-AS1 had a binding site that interacted with miR-24-3p.Upregulated miR-24-3p was detected in glioblastomas,displaying an inverse correlation with lncRNA DPP10-AS1 expression.MiR-24-3p downstream target has been determined as chromodomain helicase DNA binding protein 5(CHD5).LncRNA DPP10-AS1 affected the invasion and proliferation of glioblastoma by controlling the miR-24-3p/CHD5 axis.Conclusion:The present study demonstrated that lncRNA DPP10-AS1 can inhibit the invasive,migratory,and proliferative properties of glioblastoma by regulating the miR-24-3p/CHD5 signaling pathway.Consequently,lncRNA DPP10-AS1 has potential as a tumor suppressor and might be utilized for accurate diagnosis and targeted treatments of glioblastomas.展开更多
BACKGROUND Our previous study found that the telomerase-associated protein 1(TEP1,rs938886 and rs1713449)and homo sapiens RecQ like helicase 5(RECQL5,rs820196)single nucleotide polymorphisms(SNPs)were associated with ...BACKGROUND Our previous study found that the telomerase-associated protein 1(TEP1,rs938886 and rs1713449)and homo sapiens RecQ like helicase 5(RECQL5,rs820196)single nucleotide polymorphisms(SNPs)were associated with changes in heart rate(HR)≥30%during peritoneal lavage with distilled water after gastrectomy.This study established a single tube method for detecting these three SNPs using two-dimensional(2D)polymerase chain reaction(PCR),and investigated whether SNP-SNP and SNP-environment interactions increase the risk of high HR variability(HRV).AIM To investigate whether genotypes,genetic patterns,SNP-SNP and SNP-environment interactions were associated with HRV.METHODS 2D PCR was used to establish a single-tube method to detect TEP1 rs938886 and rs1713449 and RECQL5 rs820196,and the results were compared with those of sanger sequencing.After adjusting for confounders such as age,sex,smoking,hypertension,and thyroid dysfunction,a nonconditional logistic regression model was used to assess the associations between the genotypes and the genetic patterns(codominant,dominant,overdominant,recessive,and additive)of the three SNPs and a risk≥15%or≥30%of a sudden drop in HR during postoperative peritoneal lavage in patients with gastric cancer.Gene-gene and geneenvironment interactions were analyzed using generalized multifactor dimensionality reduction.RESULTS The coincidence rate between the 2D PCR and sequencing was 100%.When the HRV cutoff value was 15%,the patients with the RECQL5(rs820196)TC genotype had a higher risk of high HRV than those who had the TT genotype(odds ratio=1.97;95%CI:1.05-3.70;P=0.045).Under the codominant and overdominant models,the TC genotype of RECQL5(rs820196)was associated with a higher risk of HR decrease relative to the TT and TT+CC genotypes(P=0.031 and 0.016,respectively).When the HRV cutoff value was 30%,patients carrying the GC-TC genotypes of rs938886 and rs820196 showed a higher HRV risk when compared with the GG–TT genotype carriers(P=0.01).In the three-factor model of rs938886,rs820196,and rs1713449,patients carrying the GC-TC-CT genotype had a higher risk of HRV compared with the wild-type GG-TT-CC carriers(P=0.01).For rs820196,nonsmokers with the TC genotype had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.04).When the HRV cutoff value was 15%,patients carrying the TT-TT and the TC-CT genotypes of rs820196 and rs1713449 showed a higher HRV risk when compared with TT-CC genotype carriers(P=0.04 and 0.01,respectively).Patients carrying the GC-CT-TC genotypes of rs938886,rs1713449,and rs820196 showed a higher HRV risk compared with GG-CC-TT genotype carriers(P=0.02).When the HRV cutoff value was 15%,the best-fitting models for the interactions between the SNPs and the environment were the rs820196-smoking(P=0.022)and rs820196-hypertension(P=0.043)models.Consistent with the results of the previous grouping,for rs820196,the TC genotype nonsmokers had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.01).CONCLUSION The polymorphism of the RECQL5 and TEP1 genes were associated with HRV during peritoneal lavage with distilled water after gastrectomy.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
P68 RNA helicase is a prototypical DEAD box RNA helicase. The protein plays a very important role in early organ development and maturation. Consistent with the function of the protein in transcriptional regulation an...P68 RNA helicase is a prototypical DEAD box RNA helicase. The protein plays a very important role in early organ development and maturation. Consistent with the function of the protein in transcriptional regulation and pre-mRNA splicing, p68 was found to predominately localize in the cell nucleus. However, recent experiments demon- strate a transient cytoplasmic localization of the protein. We report here that p68 shuttles between the nucleus and the cytoplasm. The nucleocytoplasmic shuttling of p68 is mediated by two nuclear localization signal and two nuclear exporting signal sequence elements. Our experiments reveal that p68 shuttles via a classical RanGTPase-dependent pathway.展开更多
Objective To study the effect of fleroxacin （FLRX） on biological properties of Bloom （BLM） helicase catalytic core （BLM 642-2290 helicase） in vitro and the molecular mechanism of interaction between the two mol...Objective To study the effect of fleroxacin （FLRX） on biological properties of Bloom （BLM） helicase catalytic core （BLM 642-2290 helicase） in vitro and the molecular mechanism of interaction between the two molecules. Methods DNA-binding and unwinding activities of BLM 642-1290 helicase were assayed by fluorescence polarization and gel retardation assay under conditions that the helicase was subjected to different concentrations of FLRX. Effect of FLRX on helicase ATPase activity was analyzed by phosphorus-free assay based on a colorimetric estimation of ATP hydrolysis-produced inorganic phosphate. Molecular mechanism of interaction between the two molecules was assayed by ultraviolet and fluorescence spectra. Results The DNA unwinding and ATPase activities of BLM 642-1290 helicase were inhibited whereas the DNA-binding activity was promoted in vitro. A BLM-FLRX complex was formed through one binding site, electrostatic and hydrophobic interaction force. Moreover, the intrinsic fluorescence of the helicase was quenched by FLRX as a result of non-radioactive energy transfer. The biological activity of helicase was affected by FLRX, which may be through an allosteric mechanism and stabilization of enzyme conformation in low helicase activity state, disruption of the coupling of ATP hydrolysis to unwinding, and blocking helicase translocation on DNA strands. Conclusion FLRX may affect the biological activities and conformation of BLM 642-1290 helicase, and DNA helicase may be used as a promising drug target for some diseases.展开更多
Flaviviruses are positive-sense RNA viruses, and many are important human pathogens. Nonstructural protein 2B and 3 of the flaviviruses(NS2BNS3) form an endoplasmic reticulum(ER) membrane-associated hetero-dimeric com...Flaviviruses are positive-sense RNA viruses, and many are important human pathogens. Nonstructural protein 2B and 3 of the flaviviruses(NS2BNS3) form an endoplasmic reticulum(ER) membrane-associated hetero-dimeric complex through the NS2B transmembrane region. The NS2BNS3 complex is multifunctional. The N-terminal region of NS3, and its cofactor NS2B fold into a protease that is responsible for viral polyprotein processing, and the C-terminal domain of NS3 possesses NTPase/RNA helicase activities and is involved in viral RNA replication and virus particle formation. In addition, NS2BNS3 complex has also been shown to modulate viral pathogenesis and the host immune response. Because of the essential functions that the NS2BNS3 complex plays in the flavivirus life cycle, it is an attractive target for antiviral development. This review focuses on the recent biochemical and structural advances of NS2BNS3 and provides a brief update on the current status of drug development targeting this viral protein complex.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 through the Natural Science Foundation of Jiangsu Province(No.BK20201172)the Key Project of the Jiangsu Health Commission(No.ZDB2020016)the Jiangsu Province Key Research and Development Program:Social Development Project(No.BE2021653).
文摘This investigation aimed to unveil new prospective diagnosis-related biomarkers together with treatment targets against glioblastoma.Methods:The expression levels of long non-coding RNA(lncRNA)DPP10-AS1 were assessed using real-time quantitative polymerase chain reaction(RT-qPCR)within both the patient tissue specimens and glioblastoma cell lines.The relationship between lncRNA DPP10-AS1 expression in glioblastoma and patient prognosis was investigated.Cell Counting Kit-8(CCK-8),transwell,and clonogenic experiments were utilized to assess tumor cells’proliferation,invasiveness,and migratory potentials after lncRNA DPP10-AS1 expression was up or down-regulated.Using an online bioinformatics prediction tool,the intracellular localization of lncRNA DPP10-AS1 and its target miRNA were predicted,and RNA-FISH verified results.A dual-luciferase reporter experiment validated the relationship across miR-24-3p together with lncRNA DPP10-AS1.MiR-24-3p expression within glioblastoma was identified through RT-qPCR,and potential link across miR-24-3p and lncRNA DPP10-AS1 was assessed using Pearson correlation analysis.Moreover,influence from lncRNA DPP10-AS1/miR-24-3p axis upon glioblastoma cell progression was assessed in vivo via a subcutaneous xenograft tumor model.Results:The expression of lncRNA DPP10-AS1 was notably reduced in both surgical specimens of glioblastoma and the equivalent cell lines.Low level of lncRNA DPP10-AS1 in glioblastoma is following poor prognosis.The downregulation of lncRNA DPP10-AS1 in glioblastoma cells resulted in enhanced cellular proliferation,migration,and invasion capabilities,accompanied by downregulated E-cadherin and upregulated vimentin and N-cadherin.Additionally,the observed upregulation of lncRNA DPP10-AS1 demonstrated a substantial inhibitory function upon proliferation,invasion,and migratory capabilities of LN229 cells.Subcellular localization disclosed that lncRNA DPP10-AS1 had a binding site that interacted with miR-24-3p.Upregulated miR-24-3p was detected in glioblastomas,displaying an inverse correlation with lncRNA DPP10-AS1 expression.MiR-24-3p downstream target has been determined as chromodomain helicase DNA binding protein 5(CHD5).LncRNA DPP10-AS1 affected the invasion and proliferation of glioblastoma by controlling the miR-24-3p/CHD5 axis.Conclusion:The present study demonstrated that lncRNA DPP10-AS1 can inhibit the invasive,migratory,and proliferative properties of glioblastoma by regulating the miR-24-3p/CHD5 signaling pathway.Consequently,lncRNA DPP10-AS1 has potential as a tumor suppressor and might be utilized for accurate diagnosis and targeted treatments of glioblastomas.
基金Changzhou Sci and Tech Program,No.CJ20210113Changzhou Health Young Talents Plan,No.CZQM2021006.
文摘BACKGROUND Our previous study found that the telomerase-associated protein 1(TEP1,rs938886 and rs1713449)and homo sapiens RecQ like helicase 5(RECQL5,rs820196)single nucleotide polymorphisms(SNPs)were associated with changes in heart rate(HR)≥30%during peritoneal lavage with distilled water after gastrectomy.This study established a single tube method for detecting these three SNPs using two-dimensional(2D)polymerase chain reaction(PCR),and investigated whether SNP-SNP and SNP-environment interactions increase the risk of high HR variability(HRV).AIM To investigate whether genotypes,genetic patterns,SNP-SNP and SNP-environment interactions were associated with HRV.METHODS 2D PCR was used to establish a single-tube method to detect TEP1 rs938886 and rs1713449 and RECQL5 rs820196,and the results were compared with those of sanger sequencing.After adjusting for confounders such as age,sex,smoking,hypertension,and thyroid dysfunction,a nonconditional logistic regression model was used to assess the associations between the genotypes and the genetic patterns(codominant,dominant,overdominant,recessive,and additive)of the three SNPs and a risk≥15%or≥30%of a sudden drop in HR during postoperative peritoneal lavage in patients with gastric cancer.Gene-gene and geneenvironment interactions were analyzed using generalized multifactor dimensionality reduction.RESULTS The coincidence rate between the 2D PCR and sequencing was 100%.When the HRV cutoff value was 15%,the patients with the RECQL5(rs820196)TC genotype had a higher risk of high HRV than those who had the TT genotype(odds ratio=1.97;95%CI:1.05-3.70;P=0.045).Under the codominant and overdominant models,the TC genotype of RECQL5(rs820196)was associated with a higher risk of HR decrease relative to the TT and TT+CC genotypes(P=0.031 and 0.016,respectively).When the HRV cutoff value was 30%,patients carrying the GC-TC genotypes of rs938886 and rs820196 showed a higher HRV risk when compared with the GG–TT genotype carriers(P=0.01).In the three-factor model of rs938886,rs820196,and rs1713449,patients carrying the GC-TC-CT genotype had a higher risk of HRV compared with the wild-type GG-TT-CC carriers(P=0.01).For rs820196,nonsmokers with the TC genotype had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.04).When the HRV cutoff value was 15%,patients carrying the TT-TT and the TC-CT genotypes of rs820196 and rs1713449 showed a higher HRV risk when compared with TT-CC genotype carriers(P=0.04 and 0.01,respectively).Patients carrying the GC-CT-TC genotypes of rs938886,rs1713449,and rs820196 showed a higher HRV risk compared with GG-CC-TT genotype carriers(P=0.02).When the HRV cutoff value was 15%,the best-fitting models for the interactions between the SNPs and the environment were the rs820196-smoking(P=0.022)and rs820196-hypertension(P=0.043)models.Consistent with the results of the previous grouping,for rs820196,the TC genotype nonsmokers had a higher HRV risk compared with nonsmokers carrying the TT genotype(P=0.01).CONCLUSION The polymorphism of the RECQL5 and TEP1 genes were associated with HRV during peritoneal lavage with distilled water after gastrectomy.
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.
文摘P68 RNA helicase is a prototypical DEAD box RNA helicase. The protein plays a very important role in early organ development and maturation. Consistent with the function of the protein in transcriptional regulation and pre-mRNA splicing, p68 was found to predominately localize in the cell nucleus. However, recent experiments demon- strate a transient cytoplasmic localization of the protein. We report here that p68 shuttles between the nucleus and the cytoplasm. The nucleocytoplasmic shuttling of p68 is mediated by two nuclear localization signal and two nuclear exporting signal sequence elements. Our experiments reveal that p68 shuttles via a classical RanGTPase-dependent pathway.
基金supported by the National Basic Research Program of China (No.2010CB534912)the Doctoral Program of the Ministry of Education (No.200806570003)+1 种基金the Governor of Guizhou Province Talents Fund (No.200822)Guizhou University innovation fundsfor graduate student (No. Nongke 2012027)
文摘Objective To study the effect of fleroxacin （FLRX） on biological properties of Bloom （BLM） helicase catalytic core （BLM 642-2290 helicase） in vitro and the molecular mechanism of interaction between the two molecules. Methods DNA-binding and unwinding activities of BLM 642-1290 helicase were assayed by fluorescence polarization and gel retardation assay under conditions that the helicase was subjected to different concentrations of FLRX. Effect of FLRX on helicase ATPase activity was analyzed by phosphorus-free assay based on a colorimetric estimation of ATP hydrolysis-produced inorganic phosphate. Molecular mechanism of interaction between the two molecules was assayed by ultraviolet and fluorescence spectra. Results The DNA unwinding and ATPase activities of BLM 642-1290 helicase were inhibited whereas the DNA-binding activity was promoted in vitro. A BLM-FLRX complex was formed through one binding site, electrostatic and hydrophobic interaction force. Moreover, the intrinsic fluorescence of the helicase was quenched by FLRX as a result of non-radioactive energy transfer. The biological activity of helicase was affected by FLRX, which may be through an allosteric mechanism and stabilization of enzyme conformation in low helicase activity state, disruption of the coupling of ATP hydrolysis to unwinding, and blocking helicase translocation on DNA strands. Conclusion FLRX may affect the biological activities and conformation of BLM 642-1290 helicase, and DNA helicase may be used as a promising drug target for some diseases.
文摘Flaviviruses are positive-sense RNA viruses, and many are important human pathogens. Nonstructural protein 2B and 3 of the flaviviruses(NS2BNS3) form an endoplasmic reticulum(ER) membrane-associated hetero-dimeric complex through the NS2B transmembrane region. The NS2BNS3 complex is multifunctional. The N-terminal region of NS3, and its cofactor NS2B fold into a protease that is responsible for viral polyprotein processing, and the C-terminal domain of NS3 possesses NTPase/RNA helicase activities and is involved in viral RNA replication and virus particle formation. In addition, NS2BNS3 complex has also been shown to modulate viral pathogenesis and the host immune response. Because of the essential functions that the NS2BNS3 complex plays in the flavivirus life cycle, it is an attractive target for antiviral development. This review focuses on the recent biochemical and structural advances of NS2BNS3 and provides a brief update on the current status of drug development targeting this viral protein complex.
