ABSTRACT
Identification of elements that control the initiation of transcription is a crucial step in understanding the regulation of eukaryotic gene expression. Approaches to the problem of transcriptional control with animal viruses as a model system have recently uncovered transcriptional regulatory elements, called enhancers. This chapter utilizes the human papovavirus BKV as a viral model of eukaryotic transcriptional control. The 68-bp BKV triplication functions as an enhancer element for gene expression in a number of cell types without a pronounced host cell preference. To investigate the possibility that viral enhancers may have cellular homologs, we screened a human genomic λ library for sequences related to the BKV tandem triplication with the 216-bp BKV Hae III fragment as a probe. The sequence length and arrangement of the human genomic tandem repeats is different from that of the BKV enhancer, certain similarities such as the core region and the glycoprotein-rich hexanucleotides are impressive.
