学科分类
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2 个结果
  • 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。

  • 标签: DNA结合活性 端粒长度 DNA结合蛋白 弱相互作用 端粒DNA 分子机制
  • 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