Bulla G A, Siddiqui A
Department of Microbiology and Immunology, University of Colorado School of Medicine, Denver 80262.
J Virol. 1988 Apr;62(4):1437-41. doi: 10.1128/JVI.62.4.1437-1441.1988.
We have used a transient expression system to examine the influence of the hepatitis B virus enhancer on the transcription of the hepatitis B virus surface antigen (HBsAg) gene. This enhancer is located 3' to HBsAg coding sequences but is contained within the mature HBsAg transcripts. Removal of the enhancer resulted in a significant reduction in HBsAg gene expression in liver cells. By using an in vitro nuclear run-on assay, this effect was determined to be at the level of transcription. We have further noted that HBsAg expression can be restored by the reinsertion of the enhancer sequences in the enhancerless vector. However, this reconstitution of HBsAg expression appears to depend on location of the enhancer with regard to the HBsAg promoters.
我们利用瞬时表达系统来研究乙型肝炎病毒增强子对乙型肝炎病毒表面抗原（HBsAg）基因转录的影响。该增强子位于HBsAg编码序列的3'端，但包含在成熟的HBsAg转录本中。去除增强子会导致肝细胞中HBsAg基因表达显著降低。通过体外细胞核连续转录分析，确定这种效应发生在转录水平。我们还进一步注意到，在无增强子载体中重新插入增强子序列可恢复HBsAg表达。然而，HBsAg表达的这种重建似乎取决于增强子相对于HBsAg启动子的位置。
