学科分类
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10 个结果
  • 简介:MYB蛋白质在真核细胞的有机体起重要作用。在植物,R1R2R3类型MYB蛋白质在房间周期控制工作。然而,R2R3类型MYB蛋白质是否也涉及房间部门过程,仍然保持未知。这里,我们报导那R2R3类型抄写因素基因,AtMYB59,涉及房间周期前进和根生长的规定。AtMYB59蛋白质在洋葱的原子核是局部性的表皮的房间并且transactivation活动。在酵母房间的AtMYB59的表示压制房间增长,和transformants与更长的房间有更多的原子核和更高的aneuploidDNA内容。在AtMYB59的保存领域的变化在酵母细胞生长上废除它的效果。在同步Arabidopsis房间暂停,AtMYB59基因明确地在房间周期前进期间在S阶段被表示。表示和promoter-GUS分析表明AtMYB59基因富有地在根被表示。转基因的植物overexpressingAtMYB59更短的根与野类型的植物(Arabidopsis就职Col-0)相比,并且在在根尖端的有丝分裂的房间的一半附近在中期。相反地,空变异的myb59-1比关口在中期让更长的根和更少有丝分裂的房间,建议那AtMYB59可以由扩大有丝分裂的房间的中期禁止根生长。AtMYB59调整许多下游的基因,包括CYCB1;1基因,可能通过到MYB应答的元素的绑定。这些结果在细胞周期规定和植物根生长为AtMYB59支持一个角色。

  • 标签: 转录因子基因 周期进程 根系生长 拟南芥 细胞
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  • 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.

  • 标签: B淋巴细胞 B细胞受体 AICD 激活诱发细胞死亡 mIgM 细胞生长停滞
  • 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.

  • 标签: B淋巴细胞 FAS介导 细胞凋亡 FAIM FLIP CD40
  • 简介:<正>ThesusceptibilityofprimaryBcellstoFas(APO-1,CD95)-mediatedapoptosisisregulatedbysignalsderivedfromadditionalsurfacereceptors.CD40engagementproducesupregulationofFasexpressionandinducesmarkedsensitivitytoFas-inducedcelldeath,whereasBcellantigenreceptor(BCR)engagementinhibitsFaskillingandtherebyproducesFas-resistance,eveninotherwisesusceptible,CD40-stimulatedtargets.BCRsignalingforinducibleFas-resistancedevelopsoveraperiodof12hoursanddependson

  • 标签: 初级B淋巴细胞 Fas介导细胞凋亡 耐受性 信号转导
  • 简介:被象染色体冷凝作用,面向双性人的锭子形成,染色体大会离子,分离和胞质分裂那样的一系列紧安排的事件精确通过有丝分裂调整。染色体运动被和位于着丝点以内的一个专业化染色体领域的锭子微导管的相互作用在有丝分裂期间管理。这个专业化区域,叫了kinetochore,是为锭子微导管着丝点的地点协会。除了用作在染色体和锭子微导管之间的一个物理连接,kinetochore通过微导管马达和定位在或在它附近的锭子集会检查点(囊)传感器在chromosomal分离展出一个活跃角色[例如,1]。

  • 标签: 细胞周期蛋白B1 交响乐 管弦乐队 有丝分裂 导体
  • 简介:Amajorproblemwhichispoorlyunderstoodinthemanagementofbladdercancerislowsensitivitytochemotherapyandhighrecurrenceaftertransurethralresection.Insulin-likegrowthfactor1receptor(IGF-1R)signalingplaysaveryimportantroleinprogression,invasionandmetastasisofbladdercancercells.Inthisstudy,weinvestigatedwhetherIGF-1Rwasinvolvedinthegrowthstimulatingactivityanddrugresistanceofbladdercancercells.Theresultsshowed:ThemRNAsofIGF-1,IGF-2andIGF-1Rwerestronglyexpressedinserum-freeculturedT24cellline,whereasnormalurothelialcellsdidnotexpressthesefactors/receptorsoronlyintracelevels;T24cellrespondedfarbettertogrowthstimulationbyIGF-1thandidnormalurothelialcells;blockageofIGF1Rbyantisenseoligodeoxynucleotide(ODN)significantlyinhibitedthegrowthofT24cellandenhancedsensitivityandapoptosisofT24cellstomitomycin(MMC).TheseresultssuggestedthatblockageofIGF-IRsignalingmightpotentiallycontributetothetreatmentofbladdercancercellswhichareinsensitivetochemotherapy.

  • 标签: 胰岛素生长因子-1受体 信号系统 抗药性 细胞凋亡 膀胱癌
  • 简介:<正>WeandothershavefirmlyestablishedthatsurfaceIgMreceptor(sIgM-R)crosslinkingwithantibodiestotheiheavychain(anti-i)leadstogrowtharrestandapoptosisinaseriesofwellcharacterizedB-celllymphomas.Thisrequiresablationofc-Mycproteinexpressionandtheconcomitantinductionofthecyclin-dependent-kinaseinhibitor,p27Kip1.Thesignalingmechanismsregulatingc-Mycandp27Kip1proteinexpressionarepoorlyunderstood.However,werecentlyestablishedthatsIgM-Rmediateddown-modulationofthePI-3Kpathwaydirectlyaffectedc-Mycandp27Kip1expressionandaccuratelypredictedgrowtharrest

  • 标签: CH12B细胞淋巴瘤 细胞生长阻滞 细胞凋亡 PI-3K通路 信号转导 IgM受体抗体