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23 个结果
  • 简介:Thereareabout17chromosomesinyeastSaccharomycescerevisiae.Amiddlesizedchromosome,chromosomeV,waschoseninthisworkforstudyingandconstructingthephysi-calmaps.ChromosomeVfromstrainA364awasisolatedbypulsed-fieldgradientgelelectrophoresis(PFGE).GelslicescontainingchromosomeVDNAweredigestedwithtworarecuttingenzymes,NotⅠandSfiⅠ,andthree6-Ntrecognizingenzymes,SmaⅠ,SstⅡandApaⅠ.Severalstrategies-partialorcompletedigestions,digestionwithdifferentsetsoftwoenzymes,andhybrid-izationwithclonedgeneticallymappedprobes(CAN1,URA3,CEN5,PRO3,CHO1,SUP19,RAD51,RAD3)——wereusedtoaligntherestrictionfragments.Thereare9,9,15,17,and20sitesforNotⅠ,SfiⅠ,SmaⅠ,SstⅡandApaⅠrespectivelyinthemapoftheA364achromosomeV.Itstotallengthwascalculatedtobe620Kb(Kilo-bases).Thedistributionsofthecuttingsitesforthesefiveenzymesthroughthewholechromosomearenotuniform.Acomp-arisonbetweenthephysicalmapandthegeneticmapwasalsomade.

  • 标签: YEAST chromcsome V macro-physical map DNA
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  • 简介:Mammaliancelltotipotencyisasubjectthathasfascinatedscientistsforgenerations.AlonglastingquestionwhethersomeofthesomaticcellsretainstotipotencywasansweredbythecloningofDollyattheendofthe20thcentury.Thedawnofthe218thasbroughtforwardgreatexpectationsinharnessingthepoweroftotipotentcyinmedicine.Throughstemcellbiology,itispossibletogenerateanypartsofthehumanbodybystemcellengineering.Considerableresourceswillbedevotedtoharnesstheuntappedpotentialsofstemcellsintheforeseeablefuturewhichmaytransformmedicineasweknowtoday.Atthemolecularlevel,totipotencyhasbeenlinkedtoasingulartranscriptionfactoranditsexpressionappearstodefinewhetheracellshouldbetotipotent.NamedOct4,itcanactivateorrepresstheexpressionofvariousgenes.Curiously,verylittleisknownaboutOct4beyonditsabilitytoregulategeneexpression.ThemechanismbywhichOct4specifiestotipotencyremainsentirelyunresolved.Inthisreview,wesummarizerethestructureandfunctionofOct4andaddresstoOct4functioninmaintainingtotipotencyorpluripotencyofembryonicstemcels.

  • 标签: 干细胞 全能性 复制 翻译 蛋白因子
  • 简介:InteractionbetweencytotoxicTlymphocyte-associatedantigen-4(CTLA4,CD152)andB7molecules(B7-1andB7-2)isofimportanceinthecellulareventsoflymphocyte,includingantigen-specificT-cellactivationandinductionofautoreactiveT-cell.WedescribehaerethefirstintroductionofamurinesolubleCTLA4gene,CTLA4Ig,toMm1cells,amacrophagiccellline.CTLA4IgwassuccessfullyexpressedonMm1cellsandtheexpressedCTLA4IgwasfoundtobefunctionallyactiveintheirbindingtoB7moleculesbyflowcytometryandimmunofluorescencestudies.ThebiologicalactivityofCTLA4IgfromthetransfectedMm1cellswasstudiedandshowedinhibitoryactivityonmixedlymphocyteculture.AhighCTLA4Igproducingmacrophagiccelllinewasobtained.AsMm1cellswereregardedasdifficultforgenetransfectionandtherehassofarbeennoreportonexpressionofCTLA4IggeneonMm1cells,theseresultssuggestedthattheCELA4IgexpressingMm1cellscouldbeusefulforanalysisofCTLA4andB8moleculeinteractioninbothmacrophageandT-cell.

  • 标签: T淋巴细胞相关抗原4 细胞毒 可溶型 巨噬细胞 生物学活性 表达
  • 简介:Trichosanthin(TCS)isapotentallergentomice.Accordingtoourpreviousexperiments,itcouldbringouttheIgEresponsetoovabumin(OVA)ifTCSwasgivenonedaybeforeOVAimmunization,whileOVAalonecouldnotinduceIgEtoit.Inthiswork,thekineticsofinterleukin4(IL-4)andinterferonγ(IFN-γ)geneexpressioninthemesentericlymphnode(MLN)ofTCS-immunizedmicewasinvestigatedusingasemi-quantitativeRT-PCRmethod.ItindicatedthatTCSinducedsignificantIL-4geneexpressionandthepeaksofIL4geneexpressionwereondayoneafterTCSimmunizationinbothprimaryandsecondaryresponse.Incontrast,theIFN-γgeneexpressionwassuppressed.Furthermor,theIL-4geneexpressioninthesecondaryresponsewaslowerthanthatintheprimaryresponse.ThusthepresenceofIgEmemoryBcellswerestudied.ResultsshowedthattheamountofmatureIgEmRNAarosesignificantlyandrapidlyonedayafterTCSrestimulation,whileintheMLNofthemiceprimed30daysbeforeandwithoutboost,itwasalmostasthesameamountoftheunimmunizedcontrol.ThesefindingssuggesttheexistenceoftheIgEmemoryBcellsinthemiceaftertheprimaryTCSimmunization.

  • 标签: IL-4 IFN-γ Trichosansin 小鼠 免疫反应 基因表达
  • 简介:Asimplemethodtocreateachromosome-specificDNAlibrqaryofrice,includingmicrodissection,amplification,charterizationandcloning,isdescribed.Ricechromosome4fromametaphasecellhasbeenisolatedandamplifiedbytheLinkerAdapterPCR(LA-PCR).ThePCRproductswerelabeledasprobeswithDIG-11-dUTPusingtherandomprimingmethod.SouthernblotanalysiswithricegenomicDNAandspecificRFLPmarkersdemonstratedthatthePCRproductswerederivedfromricechromosome4.Alargelibrarycomprisingover100,000recombinantplasmidmicroclonesfromricechromosome4wasconstructed.Colonyhybridizationshowedthat58%oftheclonescontainedsingleorlow-copysequencesand42%containedrepetitivesequences.ThesizeofinsertsgeneratedbyPCRrangedfrom140bpto500bp.ThismethodwillfacilitatecloningofthespecificchromosomeDNAmarkersandimportantgenesofrice.

  • 标签: 水稻 第4号染色体 DNA文库 LA-PCR 显微解剖
  • 简介:真核细胞的房间的最惹人注目的形态特征是各种各样的围住膜的分隔空间的存在。包括细胞器和短暂运输中介,这些分隔空间不是静态的。更确切地说,蛋白质和膜的动态交换被需要维持细胞的动态平衡。膜动员的最戏剧的例子之一在macroautophagy的过程期间被看见。Macroautophagy是为长寿蛋白质和细胞器的降级的主要细胞的小径。响应环境暗示,例如饥饿或应力的另外的类型,房间生产唯一的膜结构,phagophore.Thephagophore扣押它形成一个双膜cytosolic泡的细胞质,anautophagosome。在结束之后,autophagosome与溶酶体熔化或在酵母的一个液泡,它交付水疗院放射激光与它的货物,和产生大分子一起毁坏内部autophagosome膜回来被释放进cytosol因为reuse.Autophagy因此是正在骑车过程,允许房间熬过滋养的限制的时期;然而,它有一个更宽的生理的角色,参予开发和老化,并且另外在对病原体侵略,癌症和某些neurodegenerative的保护疾病。在许多情况中,autophagy的角色通过autophagy相关的蛋白质的研究被识别,Atg6/Beclin1。这蛋白质是类脂化合物kinase建筑群的部分,并且最近的研究建议它在协调autophagy并且在反对apoptosis的细胞的死亡过程的thecytoprotective功能起一个中央作用。这里,我们总结我们Atg6/Beclin的当前的知识1在在细胞的不同模型有机体和它的唯一的功能。

  • 标签: 溶酶体 磷酸肌醇 蛋白质 液泡 酵母
  • 简介:Interleukin-4isacytokineproducedbyactivatedTcells,mastcells,andbasophilsthatelicitsmanyimportantbiologicalresponses[1](seeTab1).TheseresponsesrangefromtheregulationofhelperTcelldifferentiation[2]andtheproductionofIgE[3]totheregulationoftheadhesivepropertiesofendothelialcellsviaVCAM-1[4],Inkeepingwiththesediversebiologicaleffects,high-affinitybindingsitesforIL-4(Kd20to300pM)havebeendetectedonmanyhematopoieticandnon-hematopoieticcelltypesatlevelsrangingfrom50to5000sitespercell[5].ThisreviewwillfocusonthediscretesignaltransductionpathwaysactivatedbytheIL-4recxeptorandthecoordinationoftheseindividualpathwaysintheregulationofafinalbiologicaloutcome.

  • 标签: 白介素-4 基因表达 生长 细胞存活 调节 生物学作用
  • 简介:ThesplicingofmanyalternativeexonsintheprecursormessengerRNA(pre-mRNA)isregulatedbyextracellularfactorsbuttheunderlyingmolecularbasesremainunclear.HerewereportthedifferentialregulationofBcl-xpre-mRNAsplicingbyextracellularfactorsandtheirdistinctrequirementsforpre-mRNAelements.InK562leukemiacells,treatmentwithinterleukin-6(IL-6)orgranulocyte-macrophagecolonystimulatingfactor(GM-CSF)reducedtheproportionoftheBcl-xLvariantmRNAwhiletreatmentwith12-O-tetradecanoylphorbol13-acetate(TPA)hadnoeffect.InU251gliomacells,however,TPAefficientlyincreasedtheBcl-xLlevel.Theseregulationswerealsoseenforatransfectedsplicingreportermini-gene.Furtheranalysesofdeletionmutantsindicatethatnucleotides1-176ofthedownstreamintronarerequiredfortheIL-6effect,whereasadditionalnucleotides177-284areessentialfortheGM-CSFeffect.AsfortheTPAeffect,onlynucleotides1-76arerequiredinthedownstreamintron.Thus,IL-6,GM-CSFandTPAdifferentiallyregulateBcl-xsplicingandrequirespecificintronicpre-mRNAsequencesfortheirrespectiveeffects.

  • 标签: 信使RNA前体 交替剪接 BCL-X基因 白细胞间介素-6 12-氧-四价-13-醋酸酯 粒细胞-巨噬细胞菌落刺激因子
  • 简介:Perforin是主要从事调停的形成毛孔的蛋白质目标T房间死亡并且被细胞毒素的T淋巴细胞(CTL)和自然漂亮房间采用。然而,它是否也在常规CD4+T房间功能起一个作用,仍然保持不清楚。这里,我们报导那在perforin缺乏(PKO)老鼠,CD4+T房间是响应T的hyperproliferative房间受体(TCR)刺激。hyperproliferation的这个特征被改进在房间分割并且在IL-2分泌物伴随。看起来,perforin缺乏不在胸腺怒气和淋巴节点影响T房间开发。在vivo,perforin缺乏导致增加的抗原特定的T房间增长和抗体生产。而且,PKO老鼠更产生试验性的自体免疫的眼色素层炎。探讨分子的机制,我们发现在TCR刺激以后,从PKO老鼠的CD4+T房间显示增加的细胞内部的钙流动并且随后提高抄写因素NFAT1的激活。我们的结果显示perforin在由影响TCR依赖的Ca2+发信号调整CD4+T房间激活和有免疫力的反应起一个否定作用。

  • 标签: T细胞活化 CD4 钙信号 穿孔 细胞毒性T淋巴细胞 T细胞受体
  • 简介:在脂肪和肌肉房间,刺激胰岛素的葡萄糖举起被葡萄糖transporter主要调停4(GLUT4),哪个到响应胰岛素刺激的房间表面的从细胞内部的分隔空间的translocates。AS160是Akt的底层之一并且在调整胰岛素的GLUT4translocation起重要作用。在这研究,(RUVBL2)象RuvB一样蛋白质2用与集体spectrometry相结合的哺乳动物的双人脚踏车亲密关系纯化(龙头)作为新AS160有约束力的蛋白质被识别。在3T3-L1adipocytes,RUVBL2高度被表示并且在cytosol主要是分布式的。在adipocytes的RUVBL2的弄空通过减少刺激胰岛素的AS160phosphorylation禁止刺激胰岛素的GLUT4translocation和葡萄糖举起。然而,人的RUVBL2的介绍能颠倒这禁止的效果。这些数据建议RUVBL2通过它和AS160的相互作用在刺激胰岛素的GLUT4translocation起一个重要作用。

  • 标签: 结合蛋白 转位 葡萄糖转运体 串联亲和纯化 脂肪细胞 肌肉细胞
  • 简介:POU抄写因素OCT4不仅在维持pluripotent和房间而且幕作为通过基因剂量的一个房间命运决定因素完成的胚胎的茎(ES)的自我更新的状态起一个必要作用。然而,控制细胞内部的OCT4蛋白质水平的分子的机制留下逃犯。这里,我们报导那人的WWP2,E3ubiquitin(Ub)蛋白质ligase,通过它的WW领域明确地与OCT4交往并且在vitro并且在vivo提高OCT4的Ub修正。我们首先证明在人的ES房间的内长的OCT4能被Ubpost-translationally修改。而且,我们发现WWP2以一种剂量依赖者方式,和WWP2的活跃地点半胱氨酸残余通过26Sproteasome支持了OCT4的降级在OCT4上为它的酶的活动和解朊的效果被要求。显著地,我们当WWP2表示是由特定的RNA干扰(RNAi)的downregulated时,内长的OCT4蛋白质水平显著地被提高的数据表演,建议那WWP2是为在人的ES房间维持合适的OCT4蛋白质水平的一个重要管理者。而且,北污点分析证明WWP2抄本在多样的人的织物/器官是广泛地在场的并且高度在无差别的人的ES房间表示了。然而,它的表示水平快速在区分的人的ES房间以后被减少,显示WWP2表示力量发展地被调整。我们的调查结果证明WWP2是在人的ES房间的OCT4蛋白质水平的一个重要管理者。

  • 标签: 人类胚胎干细胞 转录因子 退化 蛋白质水平 Northern 半胱氨酸残基
  • 简介:兼容丑恶纸巾的表面上的花粉萌芽是为植物授精的必要的步。这里,我们报导Arabidopsis变异的bcl1是由于花粉萌芽的失败不育的男性。我们证明bcl1异种等位基因不能被男配偶体播送,没有同型结合的bcl1异种被获得。花粉发育阶段的分析显示bcl1变化影响花粉萌芽然而并非花粉成熟。分子的分析证明花粉萌芽的失败被AtBECLIN1的混乱引起。AtBECLIN1在成熟花粉主要被表示并且与重要相同编码蛋白质到在酵母为autophagyandvacuolar蛋白质排序的过程(VPS)要求的Beclin1/Atg6/Vps30。我们也证明AtBECLIN1为正常被要求植物开发,和那与autophagy,VPS和glycosylphosphatidylinositolanchor系统有关的基因,被AtBECLIN1的缺乏影响。

  • 标签: 拟南芥 AtBECLIN1 花粉萌发 植物发育
  • 简介:IL-16isaligandandchemotacticfactorforCD4+Tcells.IL-16inhibitstheCD3mediatedlymphocyteactivationandproliferation.TheeffectsofIL-16onthetargetcellsaredependentonthecelltype,thepresenceofco-activatorsetc.TounderstandtheregulationfunctionandmechanismofIL-16ontargetcells,weuseda130a.a.recombinantIL-16tostudyitseffectsonthegrowthofJurkatTleukemiacellsinvitro.WefoundthattherIL-16stimulatedtheproliferationofJurkatcellsatlowdose(10^-9M),butinhibitedthegrowthofthecellsathigherconcentration(10^-5M).Resultsshowedthat10^-5MofrIL-16treatmentinducedanenhancedapoptosisinJurkatcells.ThetreatmentblockedtheexpressionofFasL,butup-regulatedthec-mycandBidexpressioninthecells.Pre-treatmentofPKCinhibitororMEK1inhibitormarkedlyincreasedordecreasedtherIL-16inducedgrowth-inhibitingeffectsonJurkatcells,respectively.TheresultssuggestedthattherIL-16mightbearegulatorforthegrowthorapoptosisofJurkatcellsatadose-dependentmanner.Thegrowth-inhibitingeffectsofrIL-16mightbeFas/FasLindependent,but,associatedwiththeactivationofPKC,up-regulatedexpressionofc-MycandBid,andtheparticipationoftheERKsignalpathwayinJurkatcells.

  • 标签: IL-16 CD4+T细胞 趋化因子 信号传递 生长调节