Lin Na, Li Dan, Chen Hong-Ying, Chen Zhi-Xin, Wang Xiao-Zong
Department of Gastroenterology, Affiliated Union Hospital, Fujian Medical University, Fuzhou 350001, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2008 Oct;24(10):972-4.
To study the effect of HBx on a new HBx-interacted protein COXIII and mitochondria.
A recombinant eukaryotic expression plasmid pcDNA3-X was constructed, then pcDNA3-X and pcDNA3 were steadily transfected in HL-7702 separately, named HL-7702/HBx and HL-7702/pcDNA(3). The expression of COXIII in HL-7702/HBx, HL-7702/pcDNA3 and HL-7702 cells were detected by RT-PCR and western blot. Mitochondrial cytochrome c oxidase activities of three groups were assayed spectrophotometrically at 550 nm by using partially purified mitochondria.
COXIII mRNA expression didn't change, while protein expression is down-regulated in HL-7702/HBx. Cytochrome c oxidase activity was much lower in HL-7702/HBx compared with HL-7702 and HL-7702/pcDNA3 cells.
HBx can down-regulate COXIII expression through post-transcriptional level and inhibit mitochondrial cytochrome c oxidase activity.
研究HBx对一种新的与HBx相互作用的蛋白COXIII及线粒体的影响。
构建重组真核表达质粒pcDNA3-X，然后将pcDNA3-X和pcDNA3分别稳定转染至HL-7702细胞中，命名为HL-7702/HBx和HL-7702/pcDNA(3)。采用RT-PCR和蛋白质印迹法检测HL-7702/HBx、HL-7702/pcDNA3及HL-7702细胞中COXIII的表达。使用部分纯化的线粒体，通过分光光度法在550nm波长下测定三组细胞线粒体细胞色素c氧化酶的活性。
HL-7702/HBx中COXIII的mRNA表达未发生变化，但蛋白质表达下调。与HL-7702和HL-7702/pcDNA3细胞相比，HL-7702/HBx中的细胞色素c氧化酶活性低得多。
HBx可通过转录后水平下调COXIII的表达，并抑制线粒体细胞色素c氧化酶的活性。
