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89 个结果
  • 简介:Twomajorapoptosispathwayshavebeendefinedinmammaliancells,theFas/TNF-R1deathreceptorpathwayandthemitochondriapathway.TheBcl-2familyproteinsconsistofbothanti-apoptosisandpro-apoptosismembersthatregulateapoptosis,mainlybycontrollingthereleaseofcytochromecandothermitochondrialapoptoticevents.However,deathsignalsmediatedbyFas/TNF-R1receptorscanusuallyactivatecaspasesdirectly,bypassingtheneedformitochondriaandescapingtheregulationbyBcl-2familyproteins.Bidisanovelpro-apoptosisBcl-2familyproteinthatisactivatedbycaspase8inresponsetoFas/TNF-R1deathreceptorsignals.ActivatedBidistranslocatedtomitochondriaandinducescytochromecrelease,whichinturnactivatesdownstreamcaspases.Suchaconnectionbetweenthetwoapoptosispathwayscouldbeimportantforinductionofapoptosisincertaintypesofcellsandresponsibleforthepathogenesisofanumberofhumandiseases.

  • 标签: BID Bol-2家族蛋白 Fas TNF 细胞凋亡 信号传导
  • 简介:小道,肿瘤坏死因素相关导致apoptosisligand,是个新奇有势力通过房间表面死亡受体Trail-R1和Trail-R2激活房间死亡小径内长使活跃之物。它角色象在导致激活房间死亡(AICD)FasL样,在免疫系统被表明了。然而,小道机制导致了apoptosis遗体不清楚。在这份报告,重组体小道蛋白质被表示并且净化。导致apoptosis活动和JurkatT房间上重组体小道规定机制是探索试管内。Trypan蓝排除试金证明重组体小道蛋白质活跃地以种剂量依赖者方式杀死了JurkatT房间。在JurkatT房间导致小道apoptosis被Bcl-2显著地在Bcl-2基因transfected房间在表示上减少。有PMA(phorbol12十四酸盐13醋酸盐)处理,PKC使活跃之物,在JurkatT房间压制导致小道apoptosis。由PMAapoptosis抑制被预告处理二度废除,个PKC禁止者。总起来说,Bcl-2在表示上和PMA激活PKC,这被建议活跃地下面调整在JurkatT调停小道apoptosis房间。

  • 标签: TRAIL T细胞 PMA PKC BIS 细胞凋亡
  • 简介:MYB蛋白质在真核细胞有机体起重要作用。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规定。AtMYB59蛋白质在洋葱原子核是局部性表皮房间并且transactivation活动。在酵母房间AtMYB59表示压制房间增长,和transformants更长房间有更多原子核和更高aneuploidDNA内容。在AtMYB59保存领域变化在酵母细胞生长上废除它效果。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。转基因植物overexpressingAtMYB59更短野类型植物(Arabidopsis就职Col-0)相比,并且在在根尖端有丝分裂房间半附近在中期。相反地,空变异myb59-1比关口在中期让更长根和更少有丝分裂房间,建议那AtMYB59可以由扩大有丝分裂房间中期禁止根生长。AtMYB59调整许多下游基因,包括CYCB11基因,可能通过到MYB应答元素绑定。这些结果在细胞周期规定和植物根生长AtMYB59支持个角色。

  • 标签: 转录因子基因 周期进程 根系生长 拟南芥 细胞
  • 简介:新鲜水息肉水螅属于门Cnidaria,它在bilaterians外观前从后生动物系分叉。以便在metazoans理解apoptosis进化,我们开始阐明了在这个模型有机体分子细胞死亡机械。基于EST和整个水螅染色体集会,我们识别了15caspases。我们证明个人在apoptosis期间被激活,四N终端DED,卡片或DD领域有开始者caspases特征,二在vitro经历autoprocessing。另外,我们描述七Bcl-2-like和二象Bak样蛋白质。大多数Bcl-2家庭蛋白质,我们观察了mitochondrial本地化。当在哺乳动物房间表示了时,象HyBak12强烈导致apoptosis。禁止apoptosis显示出特别强壮保护效果HyBcl-2-like4在哺乳动物房间由camptothecin劝诱了六个Bcl-2家庭成员。这蛋白质也象HyBak样交往了1在酵母二混血儿试金。在它BH3领域保存白氨酸变化两个都与象HyBak样废除了相互作用1并且anti-apoptotic效果。而且,我们BH-3-only描述新奇水螅蛋白质。这些之Bcl-2-like4交往了并且在哺乳动物房间导致了apoptosis。我们数据显示房间死亡规定个复杂网络进化在多细胞组织最早、最简单水平产生了,它在此展出了复杂性实质地高级比在protostome模型有机体Caenorhabditis和果蝇。

  • 标签: CASPASE家族 半胱氨酸蛋白酶 抗凋亡作用 细胞死亡 分子机制 简单机械
  • 简介:Plasmamembrane(PM)Ca^2+-ATPaseactivityinpoplarapicalbudmeristematiccellsduringshort-day(SD)-induceddormancydevelopmentwasexaminedbyaceriumprecipitationEM-cytochemicalmethod.Ca^2+-ATPaseactivity,indicatedbythestatusofceriumphosphateprecipitatedgrains,waslocalizedmainlyontheinteriorface(cytoplasmicside)ofthePMwhenplantsweregrownunderlongdaysandreachedadeepdormancy.Afewreactionproductswerealsoobservedonthenuclearenvelope.Whenplantbudsweredevelopingdormancyafter28to42dofSDexposure,almostnoreactionproductswerepresentontheinteriorfaceofthePM.Incontrast,alargenumberofceriumphosphateprecipitatedgrainsweredistributedontheexteriorfaceofthePM.After70dofSDexposure,whenbudshaddevelopedadeepdormancy,thereactionproductsofCa^2+-ATPaseactivityagainappearedontheinteriorfaceofthePM.TheresultsseemedsuggestingthattwokindsofCa^2+-ATPasesmaybepresentonthePMduringtheSD-induceddormancyinpoplar.OneistheCa^2+-pumpingATPase,whichislocatedontheinteriorfaceofthePM,formaintainingandrestoringtheCa^2+homeostasis.Theothermightbeandecto-Ca^2+-ATPase,whichislocatedontheexteriorfaceofthePM,fortheexocytosisofcellwallmaterialsassuggestedbythefactofthecellwallthickeningduringthedormancydevelopmentinpoplar.

  • 标签: 杨树 顶芽细胞 短日照诱导休眠期 钙-ATP酶活性 质膜 电镜-细胞化学定位
  • 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.

  • 标签: p53蛋白 乳腺癌 细胞增殖 HER-2/NEU PI3K路径 基因表达