【摘要】 背景与目的:蛋白激酶CK2是一种真核细胞中普遍存在的信使非依赖性丝/苏氨酸蛋白激酶,在细胞增殖和分化、信号的传导和加工等方面起重要作用。CK2在多种白血病细胞中的活性比相应的正常组织高2～8倍,且CK2的变化与肿瘤的生长情况相关。为研究其在白血病细胞中的作用机制,本研究拟利用酵母双杂交系统从自行构建的HL鄄60细胞cDNA文库中筛选出与蛋白激酶CK2α’亚基相互作用的蛋白。方法:通过PCR扩增已构建成功的重组质粒pTHCK2A’,获得人CK2α’亚基编码区cDNA;将PstⅠ/NdeⅠ双酶切的PCR产物连接到同样酶切的“诱饵”载体pGBKT7,构建酵母双杂交穿梭表达质粒(BD质粒),经DNA测序确证及转染感受态酵母菌AH109以排除自主激活。从体外培养的HL鄄60细胞中提取总RNA,以酵母穿梭表达质粒pGADT7鄄Rec为载体,采用CLONTECHSMART(switchingmechanismat5’endofRNAtranscript)技术,在酵母细胞中构建HL鄄60细胞的酵母双杂交cDNA文库,文库质粒为AD质粒。将上述构建成功的BD质粒、AD质粒共转染感受态酵母菌AH109,进行酵母双杂交实验。以筛选真阳性克隆(即与人蛋白激酶CK2α’相互作用的蛋白)。结果:经过酵母双杂交实验,筛选出6种与蛋白激酶CK2α’相互作用蛋白,核酸序列分析及同源性检索表明,其中1个与泛素/核糖体蛋白S27a有高度?更多还原

【Abstract】 BACKGROUND & OBJECTIVE: Protein kinase CK2, a kind of ubiquitous eukaryotic messenger-independent protein serine/threonine kinase, plays a vital role in cell differentiation and proliferation, signal transduction and procession. Activity of CK2 in hematopoietic cells is 2-8 folds higher than that in relevant normal tissues, moreover changes of CK2 activity are correlated to tumor growth. In order to investigate the mechanism of its effect on hematopoietic cells, we used yeast two-hybridization screening the proteins interacting with protein kinase CK2α′ subunit from HL-60 cells cDNA library. METHODS: The target CK2α′ cDNA was obtained by amplifying recombinant plasmid pTHCK2A′, containing human protein kinase CK2α′ subunit cDNA, through polymerase chain reaction (PCR). Pst Ⅰ/Nde Ⅰ-digested PCR products were directionally cloned into DNA-BD vector pGBKT7, which had also been digested by Pst Ⅰ/Nde Ⅰ. The recombinant plasmid was named yeast two-hybridization BD bait plasmid, and confirmed by DNA sequencing, and auto-activated experiments. Total RNA of HL-60 cells was extracted, CLONTECH switching mechanism at 5′ end of RNA transcirpt method was used to construct a cDNA library in yeast cells. Library plasmid was named AD plasmid. BD plasmid and AD plasmid were co-transformed into competent yeast AH109. Yeast two-hybridization was used to screen positive clones. RESULTS: Six proteins, interacting with human protein kinase CK2α′ subunit, were screened. DNA sequencing and homology comparison showed that one of the proteins was highly homologous with ubiquitin/ribosomal protein S27a (99.8%). CONCLUSION: Using yeast two-hybridization system could screen out ubiquitin/ribosomal protein S27a, which may interact with human protein kinase CK2α′ subunit, from HL-60 cells.更多还原