简介:组蛋白甲基化是参予细胞的过程的一个多样的数组的重要epigenetic现象并且被发现了与癌症被联系。几的Recentidentification嘘一demethylases证明了那嘘一甲基化是一个可逆过程。通过一条候选人途径,我们化学上有简历作为H3K27demethylase识别了JMJD3。进HeLa房间的JMJD3的Transfection引起了整齐的乙醇H3K27的特定的减小,但是没在di-和单音的甲基H3K27上有效果,或嘘H3K4和H3K9上的一离氨酸methylations。Theenzymatic活动要求JmjC域和被建议了为余因子绑定重要的保存组氨酸。试管内生物化学的实验证明那JMJD3directly催化demethylation。另外,我们发现JMJD3起来在前列腺癌症,和它的表示调整了在变形前列腺癌症是更高的。因此,我们作为能够把整齐的乙醇组从移开的ademethylase识别了JMJD3嘘一H3离氨酸27并且起来在前列腺癌症调整了。
简介:MicroRNAs(miRNAs)是他们在植物和动物的目标基因的重要post-transcriptional管理者。miRNAs通常长是20-24核苷酸。尽管有他们的不平常地小的尺寸,miRNA基因家庭的进化历史似乎类似于编码theirprotein对应物。与在动物染色体的小却丰富的miRNA家庭相对照,植物有少数但是更大的miRNA基因家庭。植物miRNA基因家庭的成员经常是高度类似的,建议经由双人脚踏车基因复制和部分复制事件的最近的扩大。尽管许多miRNA基因越过植物种类被保存,一样的基因家庭在不同种类在尺寸和genomic组织显著地变化,它可以在目标基因规定引起剂量效果和空间、时间的差别。在这评论,我们在理解植物miRNA基因家庭的进化总结当前的进步。
简介:植物荷尔蒙植物生长素在调整植物生长和开发起一个关键作用。最近的进展在植物生长素反应小径的理解被做了,首先由在Arabidopsis的植物生长素反应异种的描述。另外,microRNAs(miRNAs)被显示了是为正常植物开发和生理学重要的基因的批评管理者。然而,很少对在miRNAs并且在正常开发期间的神经质的发信号之间的可能的相互作用被知道。这里,我们显示出那ArabidopsismicroRNA,miR167,有一个互补序列到AUXIN反应FACTOR6(ARF6)和ARF8mRNAs的部分,能为ARF8,然而并非为ARF6引起抄本降级。我们报导35S::MIR167b的phenotypic描述转基因的线,和表演转基因的线有的那严重35S::MIR167barf6arf8的类似于那些的显型加倍异种。转基因的显型建议miR167可以镇压在翻译的水平的ARF6。我们证明转基因的植物在花的机关的所有四锭盘是有缺点的。在转基因的花,细丝是反常地短的,花药不能适当地释放花粉,并且花粉谷物没发芽。我们的结果提供在表明网络支持的基因表示和植物生长素的调停miRNA的规章的小径之间的一个重要连接种繁殖开发。
简介:<正>WeandothershavefirmlyestablishedthatsurfaceIgMreceptor(sIgM-R)crosslinkingwithantibodiestotheiheavychain(anti-i)leadstogrowtharrestandapoptosisinaseriesofwellcharacterizedB-celllymphomas.Thisrequiresablationofc-Mycproteinexpressionandtheconcomitantinductionofthecyclin-dependent-kinaseinhibitor,p27Kip1.Thesignalingmechanismsregulatingc-Mycandp27Kip1proteinexpressionarepoorlyunderstood.However,werecentlyestablishedthatsIgM-Rmediateddown-modulationofthePI-3Kpathwaydirectlyaffectedc-Mycandp27Kip1expressionandaccuratelypredictedgrowtharrest
简介:死亡联系域的蛋白质Daxx施加包括调停的许多报导功能经由激活c6月N终端从FasL发信号到apoptosisapoptosis的kinase(JNK),正式就职和抑制,和染色质改变的规定。它原来从酵母被克隆用船边交货对相似物体之连续感觉而形成心像口的细胞内部的尾巴的二混血儿的屏幕诱饵。而许多起始的报告仍然保持争论,Daxx在一系列压力信号包括UVirradiation,过氧化氢治疗和TGF-β治疗触发的apoptosis的规定起重要作用,是清楚的。在这评论,我们在Axinbeing上集中连接Daxx到p53的一个拴住的因素。
简介:CCAAT/enhancer有约束力的蛋白质α(C/EBPα)是transcriptional禁止细胞增殖的规章的因素,和其他的翻译开始生产二多肽,C/EBPαp30并且C/EBPαp42。由表示介绍,C/EBPαp30specifically禁止了基因的一个唯一的集合,这被揭示,包括MPP11,p84N5和SMYD2,它没被C/EBPαp影响42在两根QSG-7701hepatocyte房间线和QGY-7703hepatoma,cells.Semi量的RT-PCR分析独立地证实了这些结果。Chromatinimmunoprecipitation试金显示出30比C/EBPαp更强烈绑了在这些基因的倡导者的那C/EBPαp42。在C/EBPα是调整的down的临床的hepatoma在样品,所有三基因明确地由30在上面的C/EBPαp禁止了调整。然而,MPP11,p84N5和SMYD2genes的压抑可能直接不涉及C/EBPαp30-mediated生长抑制。我们的数据建议30调整的那C/EBPαp目标基因的一个唯一的集合并且多于C/EBPαp的dominant-negativeregulator42。
简介:在Saccharomycescerevisiae,必要基因CDC13编码telomeric遗传上并且身体上与Stn1p和Ten1p交往的搁浅单人赛的DNA有约束力的蛋白质,并且为telomere结束保护和telomere长度控制被要求。Ten1由参予telomere长度规定和染色体结束保护的分子的机制留下逃犯。在这个工作,我们用净化的recombinantCdc13p和Ten1p在胶化过滤分析观察了Cdc13p和Ten1p的一个弱相互作用。Ten1p本身展出一项弱DNA有约束力的活动,但是提高telomericTG1鈥吗?Cdc13p的DNA有约束力的能力。Cdc13p是有Ten1p的co-immunoprecipitated。在变异的ten1-55或ten1-66房间,在Ten1p和Cdc13p之间的损害相互作用与telomericDNA导致长得多的telomeres,以及Cdc13p的一个减少的协会。一致地,Ten1-55和Ten1-66异种蛋白质没能刺激telomeric在vitro的Cdc13p的DNA有约束力的活动。这些结果建议Ten1p提高telomericCdc13p到的DNA有约束力的活动否定地调整telomere长度。
简介:Uponencounteringtheantigen(Ag),theimmunesystemcaneitherdevelopaspecificimmuneresponseofenteraspecificstateofunresponsiveness,tolerance.TheresponseofBcellstotheirspecificAgcanbeactivationandproliferation,leadingtotheimmuneresponse,oranergyandactivation-inducedcelldeath(AICD),leadingtotolerance.AICDinBlymphocytesisahighlyregulatedeventinitiatedbycrosslinkingoftheBcellreceptor(BCR).BCRengagementinitiatesseveralsignalingeventssuchasactivationofPLCγ,Ras,andPI3K,whichgenerallyspeaking,leadtosurvival.However,intheabsenceofsurvivalsignals(CD40orIL-4Rengagement),BCRcrosslinkingcanalsopromoteapoptoticsignaltransductionpathwayssuchasactivationofeffectorcaspases,expressionofpro-apoptoticgenes,andinhibitionofpro-survivalgenes.ThecomplexinterplaybetweensurvivalanddeathsignalsdeterminestheBcellfateand,consequently,theimmuneresponse.
简介:OverexpressionandactivationofHER-2/neu(alsoknownasc-erbB-2),aproto-oncogene,wasfoundinabout30%ofhumanbreastcancers,promotingcancergrowthandmakingcancercellsresistanttochemo-andradio-therapy.Wild-typep53iscrucialinregulatingcellgrowthandapoptosisandisfoundtobemutatedordeletedin60-70%ofhumancancers.Andsomecancerswithawild-typep53donothavenormalp53function,suggestingthatitisimplicatedinacomplexprocessregulatedbymanyfactors.Inthepresentstudy,weshowedthattheoverexpressionofHER-2/neucoulddecreasetheamountofwild-typep53proteinviaactivatingPI3Kpathway,aswellasinducingMDM2nucleartranslocationinMCF7humanbreastcancercells.BlockageofPI3KpathwaywithitsspecificinhibitorLY294002causedG1-Sphasearrest,decreasedcellgrowthrateandincreasedchemo-andradio-therapeuticsensitivityinMCF7cellsexpressingwild-typep53.However,itdidnotincreasethesensitivitytoadriamycininMDA-MB-453breastcancercellscontainingmutantp53.OurstudyindicatesthatblockingPI3KpathwayactivationmediatedbyHER-2/neuoverexpressionmaybeusefulinthetreatmentofbreasttumorswithHER-2/neuoverexpressionandwild-typep53.
简介:TheundecapeptidesubstanceP(SP)wasshowntobeintimatelyinvolvedinboththestructuralandfunctionalaspectsoftheanteriorpituitary.Yet,inadditiontoitsinfluencesonhormonalsecretion,SPmaywellpossessmoreactionsinthismastergland.ThepresentstudywasfthereforeaimedtoinvestigatetheeffectofSPontheproliferationofratanteriorpituitarycellsinprimaryculture,ItwasfoundthatSPcoulddose-dependentlyincreasetheincorporationoftritiatedthymidine(3H-TdR)intoculturedanteriorpituitarycells.OthermammaliantachykininssuchasneurokininAandneurokininBhadsimilareffectbuttovaryingdegrees.TheequipotentanalogueofSP,Norleucine^11-SP(Nle^11-SP),alsoactedlikewise.withitsactionantagonizablebyspantide,aSPreceptorblocker.TofurthercharacterizethenatureofcellsresponsivetothechallengeofSP,immunocytochemicalstainingagainstS-100proteinandsomeadenohypophysealhormoneswasperformedaloneorplusautoradiography.TheresultsshowedthatthepercentageofS-100proteinimmunorectivecellswasapparentlyelevatedbytheaddtionofNle^11-Spfor48h,whichindicatesapreferentialproliferationoffolliculo-stellatecellsundertheregime.ThiswasconfirmedbyincreasesinimmunocytochemicalorautoradiographicallabellingindicesofanteriorpituitarySubstancePandanteriorpituitarycellproliferation.Cellstreatedsimilarly.Takentogether,TheseresultsrevealthatthetrophicactionofSPobservedpreviouslyinothertissuesisalsopresentatleastinculturedratanteriorpituitarycells.withrespondingcellsbeingpredominantlyfolliculo-stellatecellsastypifiedbyS-100proteinimmunoreactivity.Therefore,anintra-pituitarytrophicactionofSPinvivocouldbeanticipated.
简介:cAMPmediatedsignalingmayplayasuppressiveroleinimmuneresponse.WepreviouslyfoundthatthecAMP-elevators(CTxand8-Br-cAMP)inhibitedIL-12,IL-la,IL-6geneexpression,butincreasedthetranscriptionallevelsofIL-10andIL-1RainLPS-treatedmurineperitonealmacrophages.ThepresentstudyexaminedapossiblemolecularmechanisminvolvedincAMPelevators-inducedinhibitionofIL-12p40expressioninresponsetoLPS.OurdatademonstratedthatcAMPelevatorsdownregulatedIL-12p40mRNAexpressionandIL-12pT0productioninmurineperitonealmacrophages.SubsequentstudiesrevealedthatcAMP-elevatorsblockedphosphorylationofp38MAPK,butdidnotaffecttheactivityofNF-κBbindingtoIL-12promoter(-136/-112).ThisisthefirstreportthatcAMPelevatorsinhibitLPS-inducedIL-12productionbyamechanismthatisassociated,atleastinpart,withp38-dependentinhibitionbycAMPsignalingpathways.
简介:ApoptosisproducedinBcellsthroughFas(APO-1,CD95)triggeringisregulatedbysignalsderivedfromothersurfacereceptors:CD40engagementproducesupregulationofFasexpressionandmarkedsusceptibilitytoFas-inducedcelldeath,whereasantigenreceptorengagement,orIL-4Rengagement,inhibitsFaskillingandinsodoinginducesastateofFas-resistance,eveninotherwisesensitive,CD40-stimulatedtargets.SurfaceimmunoglobulinandIL-4RutilizeatleastpartiallydistinctpathwaystoproduceFas-resistancethatdifferentiallydependonPKCandSTAT6,respectively.Further,surfaceimmunoglobulinsignalingforinducibleFas-resistancebypassesBtk,requiresNF-κB,andentailsnewmacromolecularsynthesis.TerminaleffectorsofBcellFas-resistanceincludetheknownanti-apoptoticgeneproducts,Bcl-XLandFLIP,andanovelanti-apoptoticgenethatencodesFAIM(FasApoptosisInhibitoryMolecule).faimwasidentifiedbydifferentialdisplayandexistsintwoalternativelysplicedforms;faim-Sisbroadlyexpressed,butfaim-Lexpressionistissue-specific.TheFAIMsequenceishighlyevolutionarilyconserved,suggestinganimportantroleforthismoleculethroughoutphylogeny.InducibleresistancetoFaskillingishypothesizedtoprotectforeignantigen-specificBcellsduringpotentiallyhazardousinteractionswithFasL-bearingTcells,whereasautoreactiveBcellsfailtobecomeFas-resistantandaredeletedviaFas-dependentcytotoxicity.InadvertentoraberrantacquisitionofFas-resistancemaypermitautoreactiveBcellstoescapeFasdeletion,andmalignantlymphocytestoimpedeanti-tumorimmunity.
简介:<正>ThesusceptibilityofprimaryBcellstoFas(APO-1,CD95)-mediatedapoptosisisregulatedbysignalsderivedfromadditionalsurfacereceptors.CD40engagementproducesupregulationofFasexpressionandinducesmarkedsensitivitytoFas-inducedcelldeath,whereasBcellantigenreceptor(BCR)engagementinhibitsFaskillingandtherebyproducesFas-resistance,eveninotherwisesusceptible,CD40-stimulatedtargets.BCRsignalingforinducibleFas-resistancedevelopsoveraperiodof12hoursanddependson
简介:TherearetwopossibleoutcomeswhenDNAdamageoccursinnormalmammaliancells:eitherinductionofcell-cyclecheckpointwhichinhibitstheprogressofthecellcyclesaswellasactivatesDNArepairpathways,oractivationofapoptosistoeliminatedamagedcells.Thep53tumour-suppressorgeneplaysakeyroleinselectingthesepathways.Inourpresentworks,thehumangastriccancercelllineAGSwastreatedwithtripchlorolide,apotentantitumorcompoundpurifiedfromaChineseherbTripterygiumWilfordiiHook.Singlecellgelelectrophoresis(Cometassay)showedthatthetreatmentoftripchlorolideresultedinDNAdamageinAGScells.ThedamagedAGScellswentthroughapoptosis,whichwastime-anddose-dependent.
简介:Recentstudiesindicatethatcell-cyclecheckpointsaretightlycorrelatedwiththeregulationofapoptosis,inwhichp53playsanimportantrole.OurpresentworksshowthattheexpressionofE6/E7oncogenesofhumanpapillomavirusinHeLacellsisinhibitedinthepresenceofanti-tumorreagenttripchlorolide(TC),whichresultsintheup-regulationofp53inHeLacells.Interestingly,underthesameTC-treatment,thecellsattheearlyS-phasearemoresusceptibletoapoptosisthanthoseatthemiddleS-phasealthoughp53proteinisstabilizedtothesamelevelinbothsituations.Significantdifferenceisexhibitedbetweenthetwospecifiedexpressionprofiles.Furtheranalysisdemonstratesthatanti-apoptoticgenesurvivinisup-regulatedbyp53intheTC-treatedmiddle-Scells,whereasitisdown-regulatedbyp53intheTC-treatedearly-Scells.Takentogether,thepresentstudyindicatesthatthedifferentialp53-regulatedexpressionofsurvivinatdifferentstagesofthecellcycleresultsindifferentcellularoutputsunderthesameapoptosis-inducer.