A naturally occurring deletion in the enhancer repeats of the human papovavirus BK optimizes early enhancer function at the expense of late promoter activity.
The late promoter of the human papovavirus BK (prototype) is contained within the same region of DNA as the early promoter enhancer. This region, consisting of a 68-50-68-bp repeat and the flanking region to the late side, contains elements important for both late promoter activity and enhancer function for the early transcription unit. We have studied the importance of the naturally occurring 18-bp deletion in the middle repeat by constructing three repeats containing every possible combination of the 50- and 68-bp segments and testing their abilities to promote late transcription and activate an enhancerless SV40 early promoter. We find that the wild-type configuration of repeats gives optimal enhancer function, but is less active than other combinations for late transcription. This suggests that different interactions between the transcription elements contained within the same region of DNA are responsible for modulation of early and late transcription.
Cassill
J A
JA
Department of Biology, University of California San Diego, La Jolla.
Subramani
S
S
D001739:BK Virus / Q000235:genetics*; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D011120:Polyomavirus / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid