超表达转运膜蛋白21对介导阿尔茨海默氏病γ分泌酶复合物重要组分PS-1及NCT蛋白表达量的影响  

Effects of Overexpressed Transmembrane Protein 21 on Protein Levels of Components(NCT,PS-1) of γ-Secretase Involved in Alzheimer's

作　　者：博·格日勒图[1] 董贵成[1,2] 王迎春[1] 阿拉坦高勒[1] 王静[2] 门中华[2] 赵俊利[3] 

机构地区：[1]内蒙古大学生命科学学院,内蒙古呼和浩特010021 [2]内蒙古科技大学包头师范学院,内蒙古包头014030 [3]内蒙古农业大学动物科学与医学学院,内蒙古呼和浩特010018

出　　处：《内蒙古师范大学学报（自然科学汉文版）》2009年第2期198-202,共5页Journal of Inner Mongolia Normal University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(30760212);教育部"春晖计划"基金项目(Z2004-2-15011)

摘　　要：研究转运膜蛋白21(TMP21)在小鼠胚胎成纤维细胞中超表达对PS-1及NCT蛋白表达量的影响.脂质体介导TMP21 cDNA转染敲除淀粉样前体蛋白表达基因的小鼠胚胎成纤维细胞系(MEF(KO)),以梯度浓度G418筛选TMP21表达量最高的细胞.处理超表达组(T)和对照组(C)细胞,并收集纯化过程中含γ分泌酶复合物的样本,用Western blotting检测γ分泌酶复合物重要组分Nicastrin(NCT)、Presenilin-1(PS-1)以及TMP21的蛋白表达量.结果表明,样本T1、T2及IPT2所含TMP21的蛋白表达量较相应对照组样本C1、C2和IPC2分别上升11.5%(P=0.08)、28.1%(P<0.01)及69.1%(P<0.001),提示经TMP21 cDNA转染后MEF(KO)细胞中TMP21蛋白表达明显提高,而转染组和对照组中,构成γ分泌酶复合物的重要组分NCT与PS-1蛋白表达量无明显变化.这表明在TMP21蛋白高表达状态下,不会影响MEF(KO)细胞中γ分泌酶复合物的重要组分NCT与PS-1蛋白表达量.Objective Previous studies have revealed that γ-secretase is involved in the pathogenesis of Alzheimer＇s disease. The impacts of the transmembrane protein 21 （TMP21） protein levels ofγ-secretase components were investigated in APP knockout mouse embryonic fibroblasts（MEF（KO））. Methods MEF（KO） was transfectted with TMP21 cDNA to induce protein expression. During the purification of γ-secretase, samples comprising γ- secretase complex were collected in transfection（T） or control（C） group at three phases. The samples were respectively marked as follbw. T1 and C1 which included the whole cell membrane proteins;T2 and C2 which were the lysates by CHAPSO; IPT2 and IPC2 which were prepared after co-immunoprecipitation by presenilin-1 antibody. The protein levels of TMP21 and γ-secretase components,presenilin-1（PS-1） and Nicastrin（NCT）,were detected by Western blotting. Results Compared with C1, C2 and IPC2, the protein levels of TMP21 in T1, T2 and IPT2 were, respectively,increased by 11.5%（P=0.08）,28. 1% （P〈0.01） and 69. 1% （P〈0. 001）; meanwhile,no change in protein levels of NCT and PS-1 was observed. Conclusions The protein levels of the γ-secretase components presenilin-1 （PS-1） and Nicastrin （NCT） were not impacted when the TMP21 was overexpressed.

关 键 词：脱氧核糖核酸超表达 转运膜蛋白21 Presenilin-1(PS-1) Nicastrin(NCT) 免疫印迹反应 Γ分泌酶 

分 类 号：Q55[生物学—生物化学]