【摘要】 目的了解华支睾吸虫ATP合酶b亚基(CsATP-synt_B)的虫体组织定位,并以HeLa细胞为替代模型观察其亚细胞定位。方法用CsATP-synt_B重组蛋白免疫SD大鼠,取其抗血清对华支睾吸虫成虫石蜡切片进行间接免疫荧光染色,观察CsATP-synt_B蛋白在华支睾吸虫成虫组织中的分布。根据生物信息学预测的CsATP-synt_B线粒体转运序列(MTS序列)和核定位序列(NLS序列)位置,设计4组引物[CsATP-synt_B全长序列,以及3个缺失突变体(MTS-缺失线粒体转运序列、NLS-缺失核定位序列、MTS-NLS-线粒体-核定位双缺失)引物],扩增出全长基因和3个突变体基因,构建重组质粒pEGFP-N1-CsATP-synt_B1-300、pEGFP-N1-CsATP-synt_B30-300、pEGFP-N1-CsATP-synt_B(1-238)+(257-300)及pEGFP-N1-CsATP-synt_B(30-238)+(257-300)。将这些重组质粒用阳离子脂质体转染HeLa细胞,48h后用激光共聚焦显微镜观察CsATP-synt_B全长基因和3个突变体在HeLa细胞的表达和亚细胞定位。结果CsATP-synt_B蛋白在华支睾吸虫成虫中分布较为广泛,主要分布在腹吸盘、卵巢、卵黄腺和皮层。绿色荧光蛋白GFP表明CsATP-synt_B全长序列表达于线粒体或细胞核,线粒体转运序列缺失突变体表达于细胞核,核定位序列缺失突变体表达于线粒体,双缺失突变体仅表达于胞浆。结论CsATP-synt_B蛋白在华支睾吸虫的分布与线粒体的分布一致,主要集中在能量代谢较旺盛的组织部位。CsATP-synt_B蛋白既可进入线粒体,也可进入细胞核,理论预测的定位序列得到证实。更多还原

【Abstract】 Objective To illustrate the distribution of ATP synthase b subunit in the tissue of Clonorchis sinensis adult and its subcellular mimical localization in HeLa cells.Methods With the antiserum against recombinant CsATP-synt_B protein raised from SD rats as primary antibody, paraffin sections of the adult of C.sinensis were processed by the method of fluorescent immunohistochemistry to observe the distribution of CsATP-synt_B protein in adult worm.According to the prediction by bioinformatics of the definite mitochondrial targeting sequence(MTS)and probable Bipartite nuclear localization signals(NLS_BP)in CsATP-synt_B sequence, recombinant pEGFP-N1 plasmids containing the intact and three defective CsATP-synt_B sequence with single defect of MTS or NLS_BP or double defect respectively were constructed.The recombinant plasmids and the control plasmid-pEGFP-N1, pEYFP-Mito and H2B-CFP, were transfected into the HeLa cells by LipofectamineTM 2000 reagent and the subcellular location of the GFP fusion protein was observed with confocal microscopy.Results The CsATP-synt_B protein appeared to distribute all over the adult worm, especially abundant on the acetabulum, ovary, vitellarium and tegument.The intact CsATP-synt_B was definitely expressed in mitochondria and/or nucleus of infected HeLa cells, whereas the MTS-deleted mutant only in cytoplasma and nucleus, the NLS_BP-deleted mutant in mitochondria and cytoplasm, and the double defect mutant only in cytoplasm.Conclusion The distribution of CsATP-synt_B in adult is accord with that of mitochondria, and mainly exits in the organsand the tissues of active energy metabolism.This study first predicted and confirmed that CsATP-synt_B can be expressed in the nucleus.更多还原