简介:Humantumornecrosisfactorα(hTNFα),apleiotropiccytokinewithactivitiesrangingfromhostdefensemechanismsininfectionandinjurytoseveretoxicityinsepticshockorotherrelateddiseases,isapromisingtargetfordrugscreening.UsingtheSELEX(systematicevolutionofligandsbyexponentialenrichment)process,weisolatedoligonucleotideligands(aptamers)withhighaffinitiesforhTNFα.Aptamerswereselectedfromastartingpoolof40randomizedsequencescomposedofabout1015RNAmolecules.RepresentativeaptamersweretruncatedtotheminimallengthwithhighaffinityforhTNFαandwerefurthermodifiedbyreplacementof2'-OHwith2'-Fand2'-NH2atallribopurinepositions.ThesemodifiedRNAaptamerswereresistanttonuclease.ThespecificityoftheseaptamersforhTNFαwasconfirmed,andtheiractivitytoinhibitthecytotoxicityofhTNFαonmouseL929cellswasdetermined.Resultsdemonstratedthatfour2'-NH2-modifiedaptamersboundtohTNFαwithhighaffinityandblockedthebindingofhTNFαtoitsreceptor,thusprotectingtheL929cellsfromthecytotoxicityofhTNFα.OligonucleotideaptamersdescribedherearepotentialtherapeuticsanddiagnosticsforhTNFc-relateddiseases.
简介:Domaindatabaseisessentialfordomainpropertyresearch.Eliminatingredundantinformationindatabasequeryisveryimportantfordatabasequality.Herewereportthemanualconstructionofanon-redundanthumanSH2domaindatabase.Thereare119humanSH2domainsin110SH2-containingproteins.HumanSH2swerealignedwithClustalX,andahomologoustreewasgenerated.Inthistree,proteinswithsimilarknownfunctionwereclassifiedintothesamegroup.Someproteinsinthesamegrouphavebeenreportedtohavesimilarbindingmotifsexperimentally.Thetreemightprovidecluesaboutpossiblefunctionsofhypotheticalproteinsforfurtherexperimentalverification.
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.
简介:Inourpreviousstudies,DAZAP2geneexpressionwasdown-regulatedinuntreatedpatientsofmultiplemyeloma(MM).ForbetterstudyingthestructureandfunctionofDAZAP2,afull-lengthCdnawasisolatedfrommononuclearcellsofanormalhumanbonemarrow,sequencedanddepositedtoGenbank(AY430097).ThissequencehasanidenticalORF(openreadingframe)astheNM_014764fromhumantestisandtheD31767fromhumancelllineKG-1.PhylogeneticanalysisandstructurepredictionrevealthatDAZAP2homologuesarehighlyconservedthroughoutevolutionandshareapolyprolineregionandseveralpotentialSH2/SH3bindingsites.DAZAP2occursasasingle-copygenewithafour-exonorganization.WefurthernoticedthatthefunctionalDAZAP2geneislocatedonChromosome12anditspseudogenegeneisonChromosome2withelectroniclocationofhumanchromosomeinGenbank,thoughnogeneticabnormalitiesofMMhavebeenreportedonChromosome12.TheORFofhumanDAZAP2encodesa17-kDaprotein,whichishighlysimilartomousePrtb.TheDAZAP2proteinismainlylocalizedincytoplasmwithadiscretepatternofpunctuateddistribution.DAZAP2mayassociatewithcarcinogenesisofMMandparticipateinyet-to-beidentifiedsignalingpathwaystoregulateproliferationanddifferentiationofplasmacells.