Siddiqui A, Jameel S, Mapoles J
Proc Natl Acad Sci U S A. 1987 Apr;84(8):2513-7. doi: 10.1073/pnas.84.8.2513.
The hepatitis B virus (HBV) DNA contains an open reading frame (ORF) designated X, which has the capacity to encode a protein of 16,560 Da (subtype adw). Such a protein has not been identified in either HBV particles or infected human livers, and therefore its role in the viral life cycle remains unknown. We report here the expression of the HBV X ORF in cultured cells using recombinant vectors. A protein of 16 kDa was identified by means of an antiserum prepared against a synthetic peptide and with human antisera from hepatitis B patients as well as those with hepatocellular carcinoma. Cell fractionation and immunofluorescence studies suggest a probable association with cytoskeletal components. Our studies further located a promoter sequence upstream of the X ORF, which directs the transcription of a 0.7- to 0.8-kilobase X-specific RNA in transfected human hepatoma cells.
乙肝病毒（HBV）DNA包含一个名为X的开放阅读框（ORF），它能够编码一种16,560道尔顿的蛋白质（adw亚型）。在HBV颗粒或受感染的人类肝脏中均未鉴定出这种蛋白质，因此其在病毒生命周期中的作用仍然未知。我们在此报告使用重组载体在培养细胞中表达HBV X ORF的情况。通过针对合成肽制备的抗血清以及来自乙肝患者和肝癌患者的人抗血清鉴定出了一种16 kDa的蛋白质。细胞分级分离和免疫荧光研究表明其可能与细胞骨架成分有关。我们的研究进一步确定了X ORF上游的一个启动子序列，该序列在转染的人肝癌细胞中指导0.7至0.8千碱基X特异性RNA的转录。
