学科分类
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48 个结果
  • 简介:新鲜的水息肉水螅属于门Cnidaria,它在bilaterians的外观前从后生动物的系分叉。以便在metazoans理解apoptosis的进化,我们开始阐明了在这个模型有机体的分子的细胞死亡机械。基于EST和整个水螅染色体集会,我们识别了15caspases。我们证明一个人在apoptosis期间被激活,四与N终端DED,卡片或DD领域有开始者caspases的特征,二在vitro经历autoprocessing。另外,我们描述七Bcl-2-like和二象Bak一样蛋白质。为大多数Bcl-2家庭蛋白质,我们观察了mitochondrial本地化。当在哺乳动物的房间表示了时,象HyBak一样1和2强烈导致的apoptosis。禁止的apoptosis与显示出特别强壮的保护的效果的HyBcl-2-like4在哺乳动物的房间由camptothecin劝诱了的六个Bcl-2家庭成员。这蛋白质也与象HyBak一样交往了1在酵母二混血儿的试金。在它的BH3领域的保存白氨酸的变化两个都与象HyBak一样废除了相互作用1并且anti-apoptotic效果。而且,我们BH-3-only描述新奇水螅蛋白质。这些之一与Bcl-2-like4交往了并且在哺乳动物的房间导致了apoptosis。我们的数据显示为房间死亡规定的一个复杂网络的进化在多细胞的组织的最早、最简单的水平产生了,它在此展出了一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:细胞内部的氧化还原作用动态平衡在决定肿瘤房间的敏感到导致药的apoptosis起一个关键作用。这里,我们调查了thioredoxin-1(TRX1)的角色,氧化还原作用规定的一个关键部件,在砷三氧化物(作为(2)O(3))导致的apoptosis。在HepG(2)房间的野类型的TRX1的在表示上导致了抑制当(2)O(3)导致了细胞色素c(cytoc),释放,caspase激活和apoptosis,并且由RNAi的TRX1表示的绒毛规定敏化HepG(2)房间到当(2)O(3)导致了apoptosis。有趣地,到重量的单位(32/35)的从Cys(32/35)的TRX1的活跃地点的变化从一个apoptotic保护者把这个分子变换成一个apoptotic倡导者。以理解这变换的机制,我们从老鼠肝使用了孤立的线粒体并且发现了野类型的TRX1能保护的那重组体从apoptotic的线粒体变化。相反,TRX1的变异的形式独自得到了线粒体相关的apoptotic变化,包括mitochondrial渗透转变毛孔(mPTP)洞,mitochondrial膜潜力的损失,和cyto从线粒体的c版本。这些apoptotic效果被cyclosporineA(CsA)禁止,显示指向到mPTP的那变异的TRX1。到由2,4-dinitrochlorobenzene(DNCB)的氧化形式体内的从它的减少的形式的TRX1的改变,TRXreductase的一个特定的禁止者,也敏化的HepG(2)房间到当(2)O(3)导致了apoptosis。这些数据建议TRX1由任何一个变化在由堵住cytoc版本调整apoptosis,并且在TRX1的激活起一个中央作用或活跃地点半胱氨酸的氧化可以敏化肿瘤房间到当(2)O(3)导致了apoptosis。

  • 标签: 肝癌 三氧化砷 线粒体 细胞色素 细胞凋亡
  • 简介:Amurinemacrophage-likecelllineJ774,acquired,inresponsetoLPS,anabilitytokilltumornecrosisfactor(TNF)-insensitivetargetP815mastocytomacellswhereasanothercellline,P388D1didnot,LPStriggeredsignalingmechanismsbetweenthetwocelllineswerecomparedwithanaimtoinquireaboutthepossiblenatureoftheabove-mentioneddifference,TheresultswhowedthattwocelllinesrespondtoLPS-treatmentbyparallelactivationofbothphospholipasesCandA2(PLCandPLA2)toapproximatelythesameextent.ThemaximumresponseoftothenzymesofJ774cellswasnotedwithin10minthetreatmentwhereasthatofP388D1cellsrequiredmorethan20min,TheotherpropertiesofLPS-responsiveenzymesstudiedweresimilarbetweentwocelllines,includingActivationofPLCandPLA2andPKCinmacrophagesbyLPS.Ca2+augmentationofenzymeactivation,participationofguaninenucleotidebinding(G)proteinsintheinitialactivationpreocesses,andinhibitionofenzymeactivationbythepriortreatmentofcellswithcholeraorpertussistoxinsetc.Moreover,LPS-triggeredactivationofPLCandPLA2wasfoundtobefollowedbytheincreaseofPKCactivitiesinbothcelllines.Inspiteofthesesimilarities.J774cellspossessedbothbasicandacidicformsofPKCactivities,whileP388D1cellsownedonlyPKCofbasicform,Nevertheless,thequestionwhyJ774cellsbutnotP388D1cells,canacquirethetumoricidalactivity,aganistP815,cellsfollowingLPStreatmentrematinstobeanswered.

  • 标签: 鼠巨噬细胞细胞系 磷脂酶A2 磷脂酶C 蛋白激酶C LPS诱导激活
  • 简介:Amurinemacrophage-likecellline,J774,acquried,inresponsetoLPS,anabilitytokilltumornecrosisfactor(TNF)-insensitivetargetP815mastocytomacells,whereasanothercellline,P388D1,didnot.LPS-triggeredsignalingmechanismsbetweenthetwocelllineswerecomparedwithanaimtoinquireaboutthepossiblenatureoftheabove-mentioneddifference.TheresultsshowedthattwocelllinesrespondtoLPS-treatmentbyparallelactivationofbothphospholipasesCandA2(PLCandPLA2)toapproximatelythesameextent.ThemaximumresponseofbothenzymesofJ774cellswasnotedwithin10minofthetreatment,whereasthatofP388D1cellsrequiredmorethan20min.TheotherpropertiesofLPS-responsiveenzymesstudiedweresimilarbetweentwocelllines,ineludingActivationofPLCandPLA2andPKCinmacrophagesbyLPSCa2+augmentationofenzymeactivation,participationofguaninenucleotidebinding(G)proteinsintheinitialactivationprocesses,andinhibitionofenzymeactivationbythepriortreatmentofcellswithcholeraorpartussistoxinsetc.Moreover,LPS-triggeredactivationofPLCandPLA2wasfoundtobefollowedbytheincreaseofPKCactivitiesinbothcelllines.Inspiteofthesesimilarities,J774cellspossessedbothbasicandacidicformsofPKCactivities,whileP388D1cellsownedonlyPKCofbasicform.Nevertheless,thequestionwhyJ774cells,butnotP388D1cells,canacquirethetumoricidalactiyity,aganistP815cellsfollowingLPS-treatmentremainstobeanswered.

  • 标签: MURINE macrophagss LPS-induced activation PLO PLA2
  • 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