Journal of Virology, October 1998, p. 7709-7714, Vol. 72, No. 10
Departments of Biological Chemistry and
Molecular Pharmacology1 and
Microbiology and Molecular Genetics2
and
Committee on Virology,3 Harvard
Medical School, Boston, Massachusetts 02115
Received 24 April 1998/Accepted 18 June 1998
Herpes simplex virus specifies two sets of transcripts from the
UL24 gene, short transcripts (e.g., 1.4 kb), processed at the UL24 poly(A) site, and long transcripts (e.g., 5.6 kb),
processed at the UL26 poly(A) site. The 1.4- and 5.6-kb
transcripts initiate from the same promoter but are expressed with
early and late kinetics, respectively. Measurements of
transcript levels following actinomycin D treatment of infected cells
revealed that the 1.4- and 5.6-kb UL24 transcripts have
similar stabilities, consistent with UL24 transcript
kinetics being regulated by differential polyadenylation rather than by
differential stabilities. Although the UL24 poly(A) site,
which gives rise to short transcripts, is encountered first during
processing, long transcripts processed at the UL26 site are
equally or more abundant; thus, operationally, the UL24
site is weak. Using a series of viral ICP27 mutants, we
investigated whether ICP27, which has been suggested to stimulate the
usage of weak poly(A) sites, stimulates 1.4-kb transcript accumulation. We found that accumulation of 1.4-kb transcripts did not require ICP27
during viral infection. Rather, ICP27 was required for full expression
of 5.6-kb transcripts, and the decrease in 5.6-kb transcripts relative
to 1.4-kb transcripts was not due solely to reduced DNA synthesis.
Our results indicate that temporal expression of UL24 transcripts can be regulated by differential polyadenylation and that
although ICP27 is not required for processing at the operationally weak
UL24 poly(A) site, it does modulate 5.6-kb transcript
levels at a step subsequent to transcriptional initiation.
0022-538X/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
The Role of Herpes Simplex Virus ICP27 in the
Regulation of UL24 Gene Expression by Differential
Polyadenylation

*
Corresponding author. Mailing address: Department of
Biological Chemistry and Molecular Pharmacology, Harvard Medical
School, 250 Longwood Ave., Boston, MA 02115. Phone: (617) 432-1691. Fax: (617) 432-3833. E-mail:
dcoen{at}warren.med.harvard.edu.
Present address: Millennium Pharmaceuticals, Cambridge, MA 02139.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»