Hu K Q, Siddiqui A
Department of Microbiology and Immunology, University of Colorado School of Medicine, Denver 80262.
Virology. 1991 Apr;181(2):721-6. doi: 10.1016/0042-6822(91)90906-r.
Hepatitis B virus (HBV) enhancer is a cis-acting element capable of potentiating transcription with liver cell specificity. To assess the regulatory function of the enhancer during viral gene expression, we employed whole genome transfections in both liver- and non-liver-derived cell lines and compared them with those of enhancerless genome transfections. Using a transient scheme of expression, the effect of enhancer deletion on the transcription of HBV genes was investigated. S1 nuclease analysis showed that deletion of the enhancer sequences did not alter the specificity of the HBV transcripts. Also, the nuclear run-on analysis demonstrated that the influence of enhancer on the HBV gene expression is at the transcriptional level. We further noted that in the absence of the enhancer, synthesis of the pregenomic RNA which originates from the core/pregenomic promoter was markedly affected. This result then implicates an additional role of the enhancer during the replication of HBV.
乙型肝炎病毒（HBV）增强子是一种顺式作用元件，能够增强具有肝细胞特异性的转录。为了评估增强子在病毒基因表达过程中的调控功能，我们在肝脏来源和非肝脏来源的细胞系中进行了全基因组转染，并将其与无增强子基因组转染的结果进行比较。采用瞬时表达方案，研究了增强子缺失对HBV基因转录的影响。S1核酸酶分析表明，增强子序列的缺失并未改变HBV转录本的特异性。此外，细胞核连续转录分析表明，增强子对HBV基因表达的影响是在转录水平上。我们进一步注意到，在没有增强子的情况下，源自核心/前基因组启动子的前基因组RNA的合成受到显著影响。这一结果进而暗示了增强子在HBV复制过程中的额外作用。
