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Rig-I蛋白C端Helicase结构域的原核表达、纯化及其多克隆抗体制备 被引量:4
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作者 李金鞠 任华 +2 位作者 王自强 钱旻 杜冰 《中国免疫学杂志》 CAS CSCD 北大核心 2010年第9期774-777,782,共5页
目的:为Rig-I蛋白结构与模式识别功能的深入研究提供灵敏、高效的免疫学检测试剂。方法:PCR法克隆小鼠Rig-I基因Helicase区编码序列(726~2240bp,编码241~746位氨基酸),构建带组氨酸标签的原核表达载体pET15b-mRig-I-H,阳性克隆经酶切... 目的:为Rig-I蛋白结构与模式识别功能的深入研究提供灵敏、高效的免疫学检测试剂。方法:PCR法克隆小鼠Rig-I基因Helicase区编码序列(726~2240bp,编码241~746位氨基酸),构建带组氨酸标签的原核表达载体pET15b-mRig-I-H,阳性克隆经酶切、测序鉴定后转化E.coliBL21进行诱导表达。目的蛋白电泳分离并割胶纯化后免疫家兔制备抗血清。抗血清用ELISA、Western blot、细胞免疫荧光方法进行鉴定。结果:目的蛋白在大肠杆菌中获得了高效表达,制备的抗Rig-I抗体效价达到1∶100000,Western blot、细胞免疫荧光结果显示该抗体能够有效地对细胞内Rig-I蛋白的表达水平进行检测。结论:成功地对mRig-I-H进行了原核表达、纯化,抗mRig-I-H的多克隆抗体具有较高的特异性,为进一步研究Rig-I尤其是Helicase区的结构与功能奠定了坚实的基础。 展开更多
关键词 RIG-I helicase 原核表达 多克隆抗体
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Effects of Mercury on the Structure and Activity of BLM642-1290 Recombinant Helicase 被引量:7
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作者 CHEN Xiang LUO Heng +3 位作者 DUAN LiXia XU QingHe ZHANG Yong XU HouQiang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2011年第1期47-55,共9页
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
关键词 BLM642‐1290 recombinant helicase STRUCTURE Enzyme activity MERCURY
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鸭RIG-Ⅰ蛋白C端helicase结构域和RD结构域的原核表达及其单克隆抗体的制备
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作者 臧凤霞 张雅春 +5 位作者 王伟 赵颖慧 李越 周长良 陈洪岩 孟庆文 《中国家禽》 北大核心 2014年第20期17-21,共5页
利用PCR技术将鸭维甲酸诱导基因Ⅰ(RIG-Ⅰ)helicase区和RD区部分编码序列分别进行扩增,并分别命名为c、d段;克隆到p ET30a原核表达载体,构建了重组原核表达质粒p ET30a-c和p ET30a-d,通过转化BL21(DE3)感受态菌、IPTG诱导、镍柱纯化表... 利用PCR技术将鸭维甲酸诱导基因Ⅰ(RIG-Ⅰ)helicase区和RD区部分编码序列分别进行扩增,并分别命名为c、d段;克隆到p ET30a原核表达载体,构建了重组原核表达质粒p ET30a-c和p ET30a-d,通过转化BL21(DE3)感受态菌、IPTG诱导、镍柱纯化表达蛋白,将纯化的c、d蛋白免疫小鼠制备单克隆抗体(m Ab),采用ELISA、Western blot和间接免疫荧光试验对单克隆抗体进行鉴定分析。获得鼠抗鸭RIG-Ⅰ单克隆抗体有14株与原核分段表达的c、d蛋白有良好的反应性,其中3株与真核表达的RIG-Ⅰ蛋白有良好的反应性。制备的鼠抗鸭RIG-Ⅰ单克隆抗体为RIG-Ⅰ在抗病毒天然免疫信号转导途径的研究奠定了基础。 展开更多
关键词 鸭RIG-Ⅰ helicase结构域 RD结构域 原核表达 单克隆抗体
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Potent in vitro Interference of Fleroxacin in DNA-binding,Unwinding and ATPase Activities of Bloom Helicase 被引量:2
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作者 LUO Heng XU Hou Qiang +3 位作者 CHEN Xiang DING Mei YANG Qi Xin LI Kun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第4期231-242,共12页
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
关键词 Biological activity BLM helicase FLEROXACIN Interaction mechanism
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Structural elucidation of SARS-CoV-2 vital proteins: Computational methods reveal potential drug candidates against main protease, Nsp12 polymerase and Nsp13 helicase 被引量:7
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作者 Muhammad Usman Mirza Matheus Froeyen 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2020年第4期320-328,共9页
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
关键词 SARS-CoV-2 COVID-19 outbreak CoV-Mpro CoV-Nsp12 polymerase CoV-Nsp13 helicase
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Heat shock protein 90 promotes RNA helicase DDX5 accumulation and exacerbates hepatocellular carcinoma by inhibiting autophagy 被引量:8
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作者 Ting Zhang Xinrui Yang +14 位作者 Wanping Xu Jing Wang Dawei Wu Zhixian Hong Shengxian Yuan Zhen Zeng Xiaodong Jia Shanshan Lu Rifaat Safadi Sen Han Zhihong Yang Leonard M.Neckers Suthat Liangpunsakul Weiping Zhou Yinying Lu 《Cancer Biology & Medicine》 SCIE CAS CSCD 2021年第3期693-704,共12页
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
关键词 Hepatocellular carcinoma heat shock protein 90 RNA helicase DDX5 AUTOPHAGY β-catenin pathway
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P68 RNA helicase is a nucleocytoplasmic shuttling protein 被引量:3
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作者 Haizhen Wang Xueliang Gao +2 位作者 Yun Huang Jenny Yang Zhi-Ren Liu 《Cell Research》 SCIE CAS CSCD 2009年第12期1388-1400,共13页
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
关键词 P68 RNA helicase nucleocytoplasm shuttle NLS NES DEAD box
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Understanding the interaction of hepatitis C virus with host DEAD-box RNA helicases 被引量:6
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作者 Megha Haridas Upadya Jude Juventus Aweya Yee-Joo Tan 《World Journal of Gastroenterology》 SCIE CAS 2014年第11期2913-2926,共14页
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
关键词 Hepatitis C virus Chronic hepatitis C Hepatitis C virus therapy DEAD-box helicases Host factors Hepatocellular carcinoma
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Functional interplay among the flavivirus NS3 protease, helicase, and cofactors 被引量:2
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作者 Kuohan Li Wint Wint Phoo Dahai Luo 《Virologica Sinica》 CAS CSCD 2014年第2期74-85,共12页
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
关键词 crystal structures antiviral drug target serine protease RNA helicase
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Functional analysis of helicase and three tandem HRDC domains of RecQ in Deinococcus radiodurans 被引量:1
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作者 HUANG Li-fen HUA Xiao-ting +4 位作者 LU Hui-ming GAO Guan-jun TIAN Bing SHEN Bing-hui HUA Yue-jin 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2006年第5期373-376,共4页
RecQ is a highly conserved helicase necessary for maintaining genome stability in all organisms. Genome comparison showed that a homologue of RecQ in Deinococcus radiodurans designated as DR1289 is a member of RecQ fa... RecQ is a highly conserved helicase necessary for maintaining genome stability in all organisms. Genome comparison showed that a homologue of RecQ in Deinococcus radiodurans designated as DR1289 is a member of RecQ family with unusual domain arrangement: a helicase domain, an RecQ C-terminal domain, and surprisingly three HRDC domain repeats, whose func-tion, however, remains obscure currently. Using an insertion deletion, we discovered that the DRRecQ mutation causes an increase in gamma radiation, hydroxyurea and mitomycine C and UV sensitivity. Using the shuttle plasmid pRADK, we complemented various domains of the D. radiodurans RecQ (DRRecQ) to the mutant in vivo. Results suggested that both the helicase and helicase-and-RNase-D-C-terminal (HRDC) domains are essential for complementing several phenotypes. The complementation and biochemical function of DRRecQ variants with different domains truncated in vitro suggested that both the helicase and three HRDC domains are necessary for RecQ functions in D. radiodurans, while three HRDC domains have a synergistic effect on the whole function. Our finding leads to the hypothesis that the RecF recombination pathway is likely a primary path of double strand break repair in this well-known radioresistant organism. 展开更多
关键词 RECQ Deinococcus radiodurans helicase HRDC
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Identification of the DEAD-box RNA helicase family members in grapevine reveals that VviDEADRH25a confers tolerance to drought stress 被引量:1
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作者 YANG Sheng-di GUO Da-long +6 位作者 PEI Mao-song WEI Tong-lu LIU Hai-nan BIAN Lu YU Ke-ke ZHANG Guo-hai YU Yi-he 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第5期1357-1374,共18页
Grapevine growing areas are increasingly affected by drought,which has greatly limited global wine production and quality.DEAD-box is one of the largest subfamilies of the RNA helicase family,and its members play key ... Grapevine growing areas are increasingly affected by drought,which has greatly limited global wine production and quality.DEAD-box is one of the largest subfamilies of the RNA helicase family,and its members play key roles in the growth and development of plants and their stress responses.Previous studies have shown the potential of DEAD-box genes in the drought stress responses of Arabidopsis and tomato,rice,and other crop species.However,information about DEAD-box genes in grapevine remains limited.In this report,a total of 40 DEAD-box genes were identified in grapevine and their protein sequence characteristics and gene structures were analyzed.By comparing the expression profiles of VviDEADRHs in response to drought stress in different grapevine varieties,nine candidate genes(VviDEADRH10c,-13,-22,-25a,-25b,-33,-34,-36,and-39)were screened based on expression profiling data.Combined with qRTPCR results,Vvi DEADRH25a was selected for functional verification.Heterologous overexpression of Vvi DEADRH25a in Arabidopsis showed the transgenic plants were more sensitive to drought stress than the control.Both electrolyte permeability and malondialdehyde content were significantly increased in transgenic plants,whereas the chlorophyll content and superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),and ascorbate peroxidase(APX)enzyme activities were significantly decreased.Furthermore,VviDEADRH25a-overexpressing plants showed down-regulated expression levels of several drought stress-related marker genes,namely At COR15a,At RD29A,At ERD15,and At P5CS1,which indicated that they participated in the drought stress response.In summary,this study provides new insights into the structure,evolution,and participation of DEAD-box RNA helicase genes in the response to drought stress in grapevines. 展开更多
关键词 GRAPEVINE gene family identification drought stress DEAD-box RNA helicase OVEREXPRESSION
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Chromodomain-helicase-DNA binding protein 5, 7 and pronecrotic mixed lineage kinase domain-like protein serve as potential prognostic biomarkers in patients with resected pancreatic adenocarcinomas 被引量:2
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作者 Crystal S Seldon Lauren E Colbert +3 位作者 William A Hall Sarah B Fisher David S Yu Jerome C Landry 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2016年第4期358-365,共8页
Pancreatic cancer is one of the deadliest cancers with a very poor prognosis. Recently, there has been a significant increase in research directed towards identifying potential biomarkers that can be used to diagnose ... Pancreatic cancer is one of the deadliest cancers with a very poor prognosis. Recently, there has been a significant increase in research directed towards identifying potential biomarkers that can be used to diagnose and provide prognostic information for pancreatic cancer. These markers can be used clinically to optimize and personalize therapy for individual patients. In this review, we focused on 3 biomarkers involved in the DNA damage response pathway and the necroptosis pathway: Chromodomainhelicase-DNA binding protein 5, chromodomain-helicaseDNA binding protein 7, and mixed lineage kinase domain-like protein. The aim of this article is to review present literature provided for these biomarkers and current studies in which their effectiveness as prognostic biomarkers are analyzed in order to determine their future use as biomarkers in clinical medicine. Based on the data presented, these biomarkers warrant further investigation,and should be validated in future studies. 展开更多
关键词 Chromodomain-helicase-DNA BINDING PROTEIN 5 Chromodomain-helicase-DNA BINDING PROTEIN 7 Mixed lineage kinase domain-like PROTEIN Pancreatic adenocarcinoma Biomarker
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RNA helicase DDX20 as a surrogate marker of statin activity in invasive breast cancer
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作者 ChaoWANG BeiyingQIU +6 位作者 JeanPaulTHIERY GautamSETHI PatrickJ.CASEY CelestialT.YAP SooChinLEE VinayTERGAONKAR AlanPremKUMAR 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2015年第S1期84-84,共1页
OBJECTIVE To evaluate if RNA helicase DDX20,highly expressed in triple negative breast cancer(TNBC)cells,could serve as a surrogate marker for simvastatin treatment response.METHODS We first assessed correlation betwe... OBJECTIVE To evaluate if RNA helicase DDX20,highly expressed in triple negative breast cancer(TNBC)cells,could serve as a surrogate marker for simvastatin treatment response.METHODS We first assessed correlation between 17 mevalonate pathway-related genes and expression of DDX20 in a cohort of 1325 breast cancer tumors.TNBC cells,MDA-MB-231,were then treated with simvastatin and mevalonate pathway intermediates to assess the alteration in DDX20 expression.In the mouse model,MDA-MB-231 cells were injected to tail veins of mice,groups of 8mice each were injected intraperioneally with vehicle or simvastatin 25mg·kg-1 3times a week for 6weeks.The number of metastatic colonies formed was quantified and immunohistochemical(IHC)staining of DDX20 was carried out in the lung tissues.RESULTS Among the 17 genes evaluated,positive correlation with DDX20 expression was observed in eight of them,with HMGCR having the highest correlation.Our in vitro experiments show exposure of breast cancer cells to simvastatin lead to a Rho-dependent decrease in gene expression of DDX20,leading to decreased tumor proliferation in a mevalonate pathway-dependent manner.Conversely,ectopic overexpression of DDX20 significantly abrogated the anti-metastatic activity of simvastatin.A similar observation is seen in the mouse model,where simvastatin-injected mice show significantly fewer visible lung metastases compared to placebo-fed mice.IHC staining on these lung tissues showed decreased DDX20 expression in simvastatin-injected group,corroborating our observations in vitro.CONCLUSION DDX20 is a potential surrogate marker for simvastatin treatment response in breast cancer and a long term implication of our findings is the possibility of an effective combinatorial therapeutic intervention using statins(to suppress DDX20 gene expression)and a suitable firstline agent″for the kill″of invasive breast cancer. 展开更多
关键词 RNA helicase DDX20 surrogate MARKER SIMVASTATIN BR
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Helicase activity and substrate specificity of RecQ5β
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作者 尤菁 徐雅楠 +5 位作者 李辉 吕袭明 李伟 王鹏业 窦硕星 奚绪光 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第6期499-507,共9页
RecQ5β is an essential DNA helicase in humans, playing important roles in DNA replication, repair, recombination and transcription. The unwinding activity and substrate specificity of RecQ5β is still elusive. Here, ... RecQ5β is an essential DNA helicase in humans, playing important roles in DNA replication, repair, recombination and transcription. The unwinding activity and substrate specificity of RecQ5β is still elusive. Here, we used stopped-flow kinetic method to measure the unwinding and dissociation kinetics of RecQ5β with several kinds of DNA substrates, and found that RecQ5β could well unwind ss/ds DNA, forked DNA and Holiday junction, but was compromised in unwinding blunt DNA and G-quadruplex. Rec5β has the preferred unwinding specificity for certain DNA substrates containing the junction point, which may improve the binding affinity and unwinding activity of RecQ5β. Moreover, from a comparison with the truncated RecQ5β~(1-467), we discovered that the C-terminal domain might strongly influence the unwinding activity and binding affinity of RecQ5β. These results may shed light on the physiological functions and working mechanisms of RecQ5β helicase. 展开更多
关键词 helicase RecQ5β DNA substrate specificity unwinding kinetics
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Computational biology approach to uncover hepatitis C virus helicase operation
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作者 Holger Flechsig 《World Journal of Gastroenterology》 SCIE CAS 2014年第13期3401-3409,共9页
Hepatitis C virus(HCV)helicase is a molecular motor that splits nucleic acid duplex structures during viral replication,therefore representing a promising target for antiviral treatment.Hence,a detailed understanding ... Hepatitis C virus(HCV)helicase is a molecular motor that splits nucleic acid duplex structures during viral replication,therefore representing a promising target for antiviral treatment.Hence,a detailed understanding of the mechanism by which it operates would facilitate the development of efficient drug-assisted therapies aiming to inhibit helicase activity.Despite extensive investigations performed in the past,a thorough understanding of the activity of this important protein was lacking since the underlying internal conformational motions could not be resolved.Here we review investigations that have been previously performed by us for HCV helicase.Using methods of structure-based computational modelling it became possible to follow entire operation cycles of this motor protein in structurally resolved simulations and uncover the mechanism by which it moves along the nucleic acid and accomplishes strand separation.We also discuss observations from that study in the light of recent experimental studies that confirm our findings. 展开更多
关键词 Hepatitis C virus Viral replication helicase protein Adenosine-triphosphate-induced operation Conformational motions Nucleic acid unzipping Computational biology Coarse-grained modelling Elastic-network model
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基于公共数据库筛选淋巴特异性解旋酶过表达肺腺癌细胞的差异微小RNA及其关键基因对预后的影响
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作者 刘崇梅 曾毅群 +2 位作者 许勇 陈睿鹏 高亚 《癌症进展》 2024年第6期623-629,共7页
目的 分析淋巴特异性解旋酶(LSH)在肺腺癌PC9细胞过表达后微小RNA(miRNA)的表达差异,并预测其潜在调控基因。方法 采用高通量测序技术检测LSH过表达的PC9细胞系中的总miRNA,并筛选核质比有差异的候选miRNA,采用实时荧光定量聚合酶链反应... 目的 分析淋巴特异性解旋酶(LSH)在肺腺癌PC9细胞过表达后微小RNA(miRNA)的表达差异,并预测其潜在调控基因。方法 采用高通量测序技术检测LSH过表达的PC9细胞系中的总miRNA,并筛选核质比有差异的候选miRNA,采用实时荧光定量聚合酶链反应(PCR)对候选miRNA的核质比进行验证,应用生物信息学方法对调控基因进行京都基因与基因组百科全书(KEGG)富集分析及基因本位(GO)功能富集分析,构建蛋白质-蛋白质相互作用(PPI)网络对miRNA核靶点进行筛选,利用癌症基因组图谱(TCGA)数据库探究候选靶基因对肺腺癌患者预后的影响。结果 通过对LSH过表达PC9细胞进行测序及基因差异分析,共筛选出5个核质比差异的miRNA:hsa-miRNA-30e-5p、hsa-miRNA-378i、hsa-miRNA-378f、hsa-miRNA-423-5p、hsa-miRNA-4284,其中核内miRNA-4284增加最为显著。经KEGG与GO富集分析发现这些miRNA可能通过结合靶基因参与了RAS信号通路的调控。通过PPI网络及肺癌预后预测发现,差异miRNA可下调CXC趋化因子受体4(CXCR4)表达,增加肺腺癌患者的死亡风险。结论 LSH过表达的肺腺癌PC9细胞核和细胞质中出现多个显著差异表达的miRNA,以核内miRNA-4248变化最为明显,生物信息学分析发现差异miRNA可能通过下调CXCR4的表达增加肺腺癌患者的死亡风险。 展开更多
关键词 肺癌 淋巴特异性解旋酶 微小RNA miRNA-4248 CXC趋化因子受体4
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猪肺炎支原体解螺旋酶RuvA的原核表达、多克隆抗体制备及活性鉴定 被引量:1
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作者 谢青云 邢蕙萱 +4 位作者 于岩飞 袁厅 熊祺琰 熊富强 冯志新 《畜牧兽医学报》 CAS CSCD 北大核心 2024年第1期271-281,共11页
猪肺炎支原体的持续性感染问题频发,同源重组介导的抗原变异扮演重要角色。解螺旋酶RuvA调节霍利迪连接体变构是参与同源重组的关键步骤。鉴于此,本研究旨在原核表达猪肺炎支原体解螺旋酶RuvA重组蛋白,鉴定其DNA结合活性并制备多克隆抗... 猪肺炎支原体的持续性感染问题频发,同源重组介导的抗原变异扮演重要角色。解螺旋酶RuvA调节霍利迪连接体变构是参与同源重组的关键步骤。鉴于此,本研究旨在原核表达猪肺炎支原体解螺旋酶RuvA重组蛋白,鉴定其DNA结合活性并制备多克隆抗体。试验通过分子克隆构建原核表达质粒pET21a-RuvA,经诱导表达和纯化获得RuvA M hp重组蛋白;免疫家兔制备抗RuvA M hp多克隆抗体,再利用间接ELISA和Western blot试验进行效价测定和特异性验证;利用凝胶迁移试验结合表面等离子共振技术分析RuvA M hp的DNA结合活性;利用凝胶迁移试验结合Western blot试验鉴定RuvA M hp的寡聚特性。结果显示:原核表达的RuvA M hp重组蛋白约为26 ku;制备的抗RuvA M hp多克隆抗体效价为1∶256000,且具有良好的特异性;RuvA M hp具有较强的DNA结合活性,对霍利迪连接体的亲和力高达624.4 pmol·L^(-1)(K D),并且主要以八聚体形式与其形成稳定复合物。通过RuvA M hp的原核表达、多克隆抗体制备及活性鉴定,为后续探索RuvA调解同源重组介导猪肺炎支原体抗原变异的分子机制奠定了基础。 展开更多
关键词 猪肺炎支原体 解旋酶RuvA DNA结合 多克隆抗体
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Ku70作为RNA解旋酶调节miR-124的加工成熟及神经细胞的分化
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作者 黄皑雪 李睿婷 +8 位作者 赵越超 李洁 李慧 丁学锋 王琳 肖参 刘雪梅 秦成峰 邵宁生 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2024年第6期1418-1433,共16页
目的Ku70蛋白主要通过其DNA结合特性参与双链DNA断裂(DSB)的非同源端连接(NHEJ)修复,有报道称其具有RNA结合功能,本文探索Ku70是否具有RNA解旋酶活性并影响miRNA加工成熟。方法利用RNA免疫共沉淀(RIP)测序结合生物信息学分析Ku蛋白结合... 目的Ku70蛋白主要通过其DNA结合特性参与双链DNA断裂(DSB)的非同源端连接(NHEJ)修复,有报道称其具有RNA结合功能,本文探索Ku70是否具有RNA解旋酶活性并影响miRNA加工成熟。方法利用RNA免疫共沉淀(RIP)测序结合生物信息学分析Ku蛋白结合的RNA;蛋白质印迹法(Western blot,WB)结合定量反转录PCR(qRTPCR)检测Ku蛋白与miRNAs的表达关系;生物膜干涉技术(BLI)实验分析Ku蛋白与RNA的结合能力;电泳迁移率变动分析(EMSA)实验确定Ku70及Ku80的RNA解旋酶活性;形态学检测结合WB分析Ku70调节miR-124引起的神经细胞功能变化;免疫荧光结合形态学分析寨卡病毒(ZIKV)感染后Ku70及miR-124的变化与神经元分化关联。结果研究发现,Ku70蛋白具有RNA解旋酶活性,并通过其RNA解旋酶活性影响miRNA加工成熟。Ku70缺失引起许多miRNAs上调,其中包括神经细胞特异的miR-124。在人神经前体细胞(h NPCs)和人神经母细胞瘤细胞(SH-SY5Y)中敲低Ku70可促进miR-124的成熟,从而导致上述细胞向神经元分化。本文进一步发现,ZIKV感染影响了Ku70及miR-124的表达,导致细胞形态的分化。结论本研究揭示了Ku70的一种新功能,即Ku70有可能参与miRNA的成熟调控和神经细胞的分化,并且可能是ZIKV病毒致小头症的原因之一。 展开更多
关键词 KU70 RNA解旋酶 miRNA加工成熟 miR-124 神经元分化
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RECQL4在胃癌中的表达及其与预后、免疫细胞浸润水平、药物敏感性之间的关系 被引量:1
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作者 姜德培 钟剑锋 +4 位作者 张伟康 胡志耀 文学 王新友 陈泓磊 《消化肿瘤杂志(电子版)》 2024年第1期50-57,共8页
目的探究RECQL4在胃癌组织中的表达情况,并研究其与预后、免疫细胞浸润水平以及药物敏感性之间的关系。方法通过TIMER 2.0数据库分析RECQL4在不同肿瘤中的表达差异性。通过GEPIA2数据库、GEO数据库分析RECQL4在胃癌组织中的表达水平。通... 目的探究RECQL4在胃癌组织中的表达情况,并研究其与预后、免疫细胞浸润水平以及药物敏感性之间的关系。方法通过TIMER 2.0数据库分析RECQL4在不同肿瘤中的表达差异性。通过GEPIA2数据库、GEO数据库分析RECQL4在胃癌组织中的表达水平。通过Kaplan-Meier plotter数据库对RECQL4在胃癌患者预后中的价值进行生存分析评估。通过TIMER 2.0数据库评估RECQL4的表达与免疫细胞浸润水平的相关性。应用RNAactDrug数据库揭示RECQL4分子与药物敏感性之间的关系。结果RECQL4在胃癌、结直肠癌、食管癌等肿瘤组织中高表达;RECQL4的高表达与胃癌的较差预后相关。胃癌中RECQL4 mRNA表达水平与B细胞、CD8+T细胞、CD4^(+)T细胞、树突状细胞、中性粒细胞及巨噬细胞浸润水平呈负相关。治疗胃癌的常用药物伊立替康、5-氟尿嘧啶、紫杉醇及多西他赛的敏感性均与RECQL4相关。结论RECQL4在胃癌组织中高表达,且可能与多种化疗药物敏感性相关,可作为预后不良的标志物。RECQL4高表达可抑制免疫细胞浸润,可能参与了肿瘤的免疫逃逸,促进肿瘤发展。 展开更多
关键词 胃癌 解旋酶 临床预后 免疫浸润 药物敏感性
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基于微阵列分析DDX5影响头颈部鳞状细胞癌的初步探究
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作者 刘郭琦 刘春霞 +6 位作者 王静静 左金华 王芳 宋娇娇 于栋林 马向瑞 王文龙 《实用口腔医学杂志》 CAS CSCD 北大核心 2024年第6期810-816,共7页
目的:探讨DDX5解旋酶(DDX5)在头颈部鳞状细胞癌(HNSCC)中的表达及作用。方法:组织微阵列芯片分析DDX5相关mRNA表达谱数据,并用R软件筛选差异mRNAs(DEGs)。使用GEPIA 2、TCGA数据库预测DDX5的表达水平。通过RT-qPCR、免疫组化、Western b... 目的:探讨DDX5解旋酶(DDX5)在头颈部鳞状细胞癌(HNSCC)中的表达及作用。方法:组织微阵列芯片分析DDX5相关mRNA表达谱数据,并用R软件筛选差异mRNAs(DEGs)。使用GEPIA 2、TCGA数据库预测DDX5的表达水平。通过RT-qPCR、免疫组化、Western blot检测DDX5表达水平。基于高通量测序数据筛选差异circRNAs(DECs)、差异miRNAs(DEMIs)构建DDX5竞争内源性RNA网络(ceRNA)。Cytoscape软件可视化ceRNA网络图,进一步筛选出调控轴。结果:组织芯片筛选发现HNSCC中DDX5表达上调。免疫组化验证DDX5阳性染色更集中于鳞癌细胞核;qPCR结果提示DDX5 mRNA在组织和细胞中的表达有临床意义(P<0.05);Western blot结果示DDX5蛋白在组织中高表达。在ceRNA网络中确定了相关HNSCC轴circRNA-039626-miR-222-5p-DDX5。结论:DDX5在HNSCC中高表达,并且circRNA-039626-miR-222-5p-DDX5轴可能是HNSCC发生发展的潜在调控轴。 展开更多
关键词 DDX5解旋酶 头颈部鳞状细胞癌 ceRNA 微阵列分析
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