Morgan I M, Grindlay G J, Campo M S
J Gen Virol. 1999 Jan;80 ( Pt 1):23-27. doi: 10.1099/0022-1317-80-1-23.
Bovine papillomavirus type 4 (BPV-4) is a mucosal epitheliotropic virus that is a causative agent in alimentary carcinoma of cattle. The long control region (LCR) of this virus controls expression of the transforming proteins, E8 and E7. Deletion mutants of the LCR were prepared and assayed for their ability to activate transcription from the LCR promoter in primary bovine palate keratinocytes (the natural target cell for BPV-4) and fibroblasts. The LCR was at least an order of magnitude more active in keratinocytes than in fibroblasts. An epithelial specific enhancer was identified that activated transcription from the SV40 promoter to levels identical to the full-length LCR. One of the active sites in the enhancer is 100% conserved in the LCR of human papillomavirus type 16. The results demonstrate that the BPV-4 LCR has an epithelial specific enhancer, which offers the opportunity to study epithelial specific transcriptional regulation of papillomavirus promoters.
牛乳头瘤病毒4型（BPV-4）是一种嗜黏膜上皮病毒，是牛消化道癌的病原体。该病毒的长控制区（LCR）控制转化蛋白E8和E7的表达。制备了LCR的缺失突变体，并检测其在原代牛腭角质形成细胞（BPV-4的天然靶细胞）和成纤维细胞中激活LCR启动子转录的能力。LCR在角质形成细胞中的活性比在成纤维细胞中至少高一个数量级。鉴定出一种上皮特异性增强子，它可将SV40启动子的转录激活至与全长LCR相同的水平。该增强子中的一个活性位点在人乳头瘤病毒16型的LCR中100%保守。结果表明，BPV-4 LCR具有上皮特异性增强子，这为研究乳头瘤病毒启动子的上皮特异性转录调控提供了机会。
