学科分类
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11 个结果
  • 简介:BeijinghasbeenoneoftheepicentersattackedmostseverelybytheSARS-CoV(severeacuterespiratorysyndrome-associatedcoronavirus)sincethefirstpatientwasdiagnosedinoneofthecity'shospitals.WenowreportcompletegenomesequencesoftheBJGroup,includingfourisolates(IsolatesBJ01,BJ02,BJ03,andBJ04)oftheSARS-CoV.ItisremarkablethatallmembersoftheBJGroupshareacommonhaplotype,consistingofsevenlocithatdifferentiatethegroupfromotherisolatespublishedtodate.Among42substitutionsuniquelyidentifledfromtheBJgroup,32arenon-synonymouschangesattheaminoacidlevel.Rootedphylogenetictrees,proposedonthebasisofhaplotypesandothersequencevariationsofSARS-CoVisolatesfromCanada,USA,Singapore,andChina,gaverisetodifferentparadigmsbutpositionedtheBJGroup,togetherwiththenewlydiscoveredGD01(GD-Ins29)inthesameclade,followedbytheH-UGroup(fromHongKongtoUSA)andtheH-TGroup(fromHongKongtoToronto),leavingtheSPGroup(Singapore)moredistant.ThisresultappearstosuggestapossibletransmissionpathfromGuangdongtoBeijing/HongKong,thentoothercountriesandregions.

  • 标签: SARS 冠状病毒 全基因序列 北京株
  • 简介:G-proteincoupledreceptors(GPCRs)representoneofthemostimportantclassesofdrugtargetsforpharmaceuticalindustryandplayimportantrolesincellularsignaltransduction.PredictingthecouplingspecificityofGPCRstoG-proteinsisvitalforfurtherunderstandingthemechanismofsignaltransductionandthefunctionofthereceptorswithinacell,whichcanprovidenewcluesforpharmaceuticalresearchanddevelopment.Inthisstudy,thefeaturesofaminoacidcompositionsandphysiochemicalpropertiesofthefull-lengthGPCRsequenceshavebeenanalyzedandextracted.Basedonthesefeatures,classifiershavebeendevelopedtopredictthecouplingspecificityofGPCRstoG-proteinsusingsupportvectormachines.Thetestingresultsshowthatthismethodcouldobtainbetterpredictionaccuracy.

  • 标签: G-蛋白 疾病预防 分子机制 临床表现
  • 简介:TheR(replicase)proteinistheuniquelydefinednon-structuralprotein(NSP)responsibleforRNAreplication,mutationrateorfidelity,regulationoftranscrip-tionincoronavirusesandmanyotherssRNAviruses.Basedonourcompletegenomesequencesoffourisolates(BJ01-BJ04)ofSARS-CoVfromBeijing,China,weanalyzedthestructureandpredictedfunctionsoftheRproteinincomparisonwith13otherisolatesofSARS-CoVand6othercoronaviruses.TheentireORF(open-readingframe)encodesfortwomajorenzymeactivities,RNA-dependentRNApolymerase(RdRp)andproteinaseactivities.TheRpolyproteinunder-goesacomplexproteolyticprocesstoproduce15function-relatedpeptides.Ahydrophobicdomain(HOD)andahydrophilicdomain(HID)arenewlyidentifiedwithinNSP1.ThesubstitutionrateoftheRproteinisclosetotheaverageoftheSARS-CoVgenome.ThefunctionaldomainsinallNSPsoftheRproteingivedifferentphylogeneticresultsthatsuggesttheirdifferentmutationrateunderselectivepressure.ElevenhighlyconservedregionsinRdRpandtwelvecleavagesitesby3CLP(chymotrypsin-likeprotein)havebeenidentifiedaspotentialdrugtargets.Findingssuggestthatitispossibletoobtaininformationaboutthephy-logenyofSARS-CoV,aswellaspotentialtoolsfordrugdesign,genotypinganddiagnosticsofSARS.

  • 标签: SARS 冠状病毒 R蛋白 结构 功能 基因序列
  • 简介:Microarrayhasbecomeapopularbiotechnologyinbiologicalandmedicalresearch.However,systematicandstochasticvariabilitiesinmicroarraydataareexpectedandunavoidable,resultingintheproblemthattherawmeasurementshaveinherent"noise"withinmicroarrayexperiments.Currently,logarithmicratiosareusuallyanalyzedbyvariousclusteringmethodsdirectly,whichmayintroducebiasinterpretationinidentifyinggroupsofgenesorsamples.Inthispaper,astatisticalmethodbasedonmixedmodelapproacheswasproposedformicroarraydataclusteranalysis.TheunderlyingrationaleofthismethodistopartitiontheobservedtotalgeneexpressionlevelintovariousvariationscausedbydifferentfactorsusinganANOVAmodel,andtopredictthedifferentialeffectsofGV(genebyvariety)interactionusingtheadjustedunbiasedprediction(AUP)method.ThepredictedGVinteractioneffectscanthenbeusedastheinputsofclusteranalysis.Weillustratedtheapplicationofourmethodwithageneexpressiondatasetandelucidatedtheutilityofourapproachusinganexternalvalidation.

  • 标签: 聚类基因 基因表达 微分结构 互感作用 基因多样性
  • 简介:Annotationsofcompletegenomesequencessubmitteddirectlyfromsequencingprojectsarediverseintermsofannotationstrategiesandupdatefrequencies.Theseinconsistenciesmakecomparativestudiesdifficult.Toallowrapiddataprepara-tionofalargenumberofcompletegenomes,automationandspeedareimpor-tantforgenomere-annotation.Hereweintroduceanopen-sourcerapidgenomere-annotationsoftwaresystem,Restauro-G,specializedforbacterialgenomes.Restauro-Gre-annotatesagenomebysimilaritysearchesutilizingtheBLAST-LikeAlignmentTool,referringtoproteindatabasessuchasUniProtKB,NCBInr,NCBICOGs,Pfam,andPSORTb.Re-annotationbyRestauro-Gachievedover98%accuracyformostbacterialchromosomesincomparisonwiththeoriginalmanuallycuratedannotationofEMBLreleases.Restauro-GwasdevelopedinthegenericbioinformaticsworkbenchG-languageGenomeAnalysisEnvironmentandisdistributedathttp://restauro-g.iab.keio.ac.jp/undertheGNUGeneralPublicLicense.

  • 标签: 生物信息学 基因组学 基因分析 基因解释系统
  • 简介:Thestudyofsmalldrugmoleculesinteractingwithnucleicacidsisanareaofintenseresearchthathasparticularrelevanceinourunderstandingofrelativemechanisminchemotherapeuticapplicationsandtheassociationbetweengenetics(includingsequencevariation)anddrugresponse.Inthiscontribution,wedemonstratehowthesequence-specificbindingofananticancerdrugDacarbazine(DTIC)tosinglebase(A-G)mismatchcouldbesensitivelydetectedbycombiningelectrochemicaldetectionwithbiosensingsurfacebasedongoldnanoparticles.

  • 标签: 电气化学 A-G基因 基因错配 抗癌药物 药物反应 纳米微粒
  • 简介:UnderstandingthecouplingspecificitybetweenGprotein-coupledreceptors(GPCRs)andspecificclassesofGproteinsisimportantforfurtherelucidationofreceptorfunctionswithinacell.IncreasinginformationonGPCRsequencesandtheGproteinfamilywouldfacilitatepredictionofthecouplingpropertiesofGPCRs.Inthisstudy,wedescribeanovelapproachforpredictingthecouplingspecificitybetweenGPCRsandGproteins.ThismethodusesnotonlyGPCRsequencesbutalsothefunctionalknowledgegeneratedbynaturallanguagepro-cessing,andcanachieve92.2%predictionaccuracybyusingtheC4.5algorithm.Furthermore,rulesrelatedtoGPCR-Gproteincouplingaregenerated.Thecom-binationofsequenceanalysisandtextminingimprovesthepredictionaccuracyforGPCR-Gproteincouplingspecificity,andalsoprovidescluesforunderstandingGPCRsignaling.

  • 标签: GPCR G蛋白 耦合特异性 预测 序列特征 生物机能
  • 简介:AcomputationalsystemforthepredictionandclassificationofhumanG-proteincoupledreceptors(GPCRs)hasbeendevelopedbasedonthesupportvectormachine(SVM)methodandproteinsequenceinformation.ThefeaturevectorsusedtodeveloptheSVMpredictionmodelsconsistofstatisticallysignificantfeaturesselectedfromsingleaminoacid,dipeptide,andtripeptidecompositionsofproteinsequences.Furthermore,thelengthdistributiondifferencebetweenGPCRsandnon-GPCRshasalsobeenexploitedtoimprovethepredictionperformance.ThetestingresultswithannotatedhumanproteinsequencesdemonstratethatthissystemcangetgoodperformanceforbothpredictionandclassificationofhumanGPCRs.

  • 标签: 疾病预防 识别方法 G-蛋白质 受体
  • 简介:G-proteincoupledreceptors(GPCRs)areaclassofseven-helixtransmembraneproteinsthathavebeenusedinbioinformaticsasthetargetstofacilitatedrugdiscoveryforhumandiseases.AlthoughthousandsofGPCRsequenceshavebeencollected,theligandspecificityofmanyGPCRsisstillunknownandonlyonecrystalstructureoftherhodopsin-likefamilyhasbeensolved.Therefore,identifyingGPCRtypesonlyfromsequencedatahasbecomeanimportantresearchissue.Inthisstudy,anoveltechniqueforidentifyingGPCRtypesbasedontheweightedLevenshteindistancebetweentworeceptorsequencesandthenearestneighbormethod(NNM)isintroduced,whichcandealwithreceptorsequenceswithdifferentlengthsdirectly.Inourexperimentsforclassifyingfourclasses(acetylcholine,adrenoceptor,dopamine,andserotonin)oftherhodopsin-likefamilyofGPCRs,theerrorratesfromtheleave-one-outprocedureandtheleave-half-outprocedurewere0.62%and1.24%,respectively.Theseresultsarepriortothoseofthecovariantdiscriminantalgorithm,thesupportvectormachinemethod,andtheNNMwithEuclideandistance.

  • 标签: G-蛋白 受体 遗传疾病 视紫红质
  • 简介:Werecentlyreportedtheuseofagene-trappingapproachtoisolatecellclonesinwhichareportergenehadintegratedintogenesmodulatedbyT-cellactivation.WehavenowtestedapanelofclonesfromthatreportandidentifiedtheonethatrespondstoavarietyofG-proteincoupledreceptors(GPCR).TheβlactamasetaggedEGR-3JurkatcellwasusedtodissectspecificGPCRsignalinginvivo.ThreeGPCRswerestudied,includingthechemokinereceptorCXCR4(Gicoupled)thatwasendogenouslyexpressed,theplateletactivationfactor(PAF)receptor(Gq-coupled),andβ2adrenergicreceptor(Gs-coupled)thatwasbothstablytransfected.Agonistsforeachreceptoractivatedtranscriptionoftheβ-lactamasetaggedEGR-3gene.InductionofEGR-3throughCXCR4wasblockedbypertussistoxinandPD58059,aspecificinhibitorofMEK(MAPK/ERKkinase).NeitheroftheseinhibitorsblockedisoproterenolorPAF-mediatedactivationofEGR-3.Conversely,β2-andPAF-mediatedEGR-3activationwasblockedbythep38,specificinhibitorSB580.Inaddition,bothβ2-andPAF-mediatedEGR-3activationcouldbesynergisticallyactivatedbyCXCR4activation.ThiscombinedresultindicatesthatEGR-3canbeactivatedthroughdistinctsignaltransductionpathwaysbydifferentGPCRsandthatsignalscanbeintegratedandamplifiedtoefficientlytunethelevelofactivation.

  • 标签: G-蛋白相连受体 信号通道 转移因子 EGR-3