Boshart, Michael; Weber, Frank; Rüger, Rüdiger; Dorsch-Häsler, Karoline; Jahn, Gerhard; Stoerker, Jay; Schaffner, Walter; Fleckenstein, Bernhard
The strong enhancer element in the immediate early region of the human cytomegalovirus genome.
UCLA Symposia on Molecular and Cellular Biology, New Series, 1985, -.
The human cytomegalovirus (HCMV), a
member of the herpesvirus group, was found to
possess a strong transcription enhancer in the
immediate early gene region. Co-transfection
of enhancerless SV40 DNA with randomly fragmented
HCMV DNA yielded two SV40-like recombinant
viruses , each containing HCMV DNA fragments that
were substituting for the missing SV40 enhancer.
The two inserts , 341 and 262 bp in length , are
overlapping segments of genuine viral DNA representing
part of the 5'flanking region of the
major immedistte early gene i n HCMV. Studies
with deletion mutants showed that different nonoverlapping
subsets of the HCMV enhancer region
can substitute for the 72 bp repeats of SV40.
Transient expression assays indicated that the
HCMV enhancer is significantly stronger than the
SV40 element, activating cis-linked heterologous
promoters in a wide spectrum of cultured cells.
It appears that the HCMV enhancer is positively
regulated by viral immediate early genes.