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Journal of Virology, January 1999, p. 791-796, Vol. 73, No. 1
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Down Regulation of Gene Expression by the
Vaccinia Virus D10 Protein
Teri
Shors,
James G.
Keck,
and
Bernard
Moss*
Laboratory of Viral Diseases, National
Institute of Allergy and Infectious Diseases, National Institutes
of Health, Bethesda, Maryland 20892-0445
Received 10 August 1998/Accepted 15 October 1998
 |
ABSTRACT |
Vaccinia virus genes are expressed in a sequential fashion,
suggesting a role for negative as well as positive regulatory mechanisms. A potential down regulator of gene expression was mapped by
transfection assays to vaccinia virus open reading frame D10, which
encodes a protein with no previously known function. Inhibition was
independent of the promoter type used for the reporter gene, indicating
that the mechanism did not involve promoter sequence recognition. The
inhibition was overcome, however, when the open reading frame of
the reporter gene was preceded by the encephalomyocarditis virus internal ribosome entry site, which excludes the possibility of
nonspecific metabolic or other antiviral effects and suggests that
capped mRNAs or cap-dependent translation might be the target of the D10 product. The inducible overexpression of the D10 gene by a
recombinant vaccinia virus severely inhibited viral protein synthesis,
decreased the steady-state level of viral late mRNA, and blocked the
formation of infectious virus.
| |
TEXT |
Vaccinia virus contains nearly 200 genes (20) that can be divided into three
classes
early, intermediate, and latebased on their times of
expression (29, 33), promoter consensus sequences (2,
11, 12), and specific transcription factor requirements (9,
22, 41). Early gene expression is unique in that it does
not require the de novo synthesis of DNA or proteins since the
template, viral RNA polymerase, and early transcription factors are
present within the infectious virus particle (21, 30). The
early transcription factors, like virion structural proteins, are
synthesized at late times (1, 8, 17). The viral proteins
needed for intermediate transcription are products of early genes
(34, 35, 41, 42), whereas at least some of those required
for late transcription are products of intermediate genes (19, 22,
32, 47), providing the basis for sequential regulation.
At present, only positive regulators of poxvirus gene expression have
been described. However, the rapidity of the shifts in cellular and
viral protein synthesis raises the possibility of a role for negative
regulators. The sharp increase in the rates of decay of host and viral
mRNAs during vaccinia virus infection may accelerate progression
through the stages of host and early, intermediate, and late viral gene
expression (3, 31, 37). Stage-specific repressors of
transcription and translation also have been suggested but without
supporting evidence.
Inhibition of reporter gene expression by the D10 ORF.
The
present study originated from an unbiased screen of the vaccinia virus
genome for transactivators of viral late gene expression (22). In cells infected with vaccinia virus in the presence of cytosine arabinoside, an inhibitor of DNA replication, reporter gene
expression was activated upon transfection of specific combinations of
six cosmids containing cloned fragments that spanned the entire vaccinia virus genome. The activators were mapped to the G8, A1, and A2 open reading frames (ORFs) (22), and the proteins
were later shown to be transcription factors. We had noted in
some experiments that the omission of cosmid 10 increased reporter gene
activity severalfold in this assay (data not shown). Since the
HindIII D DNA segment of the vaccinia virus genome was
unique to cosmid 10, multiple plasmids that contained DNA from that
region were tested for inhibitory activity in transfection assays using reporter plasmids with Escherichia coli lacZ under
control of the vaccinia virus late P11 promoter (4). These
experiments were performed with cells infected with vaccinia
virus in the absence of cytosine arabinoside. In contrast to the vector
alone, one plasmid containing a 2.9-kbp segment that included the D9, D10, and D11 ORFs inhibited lacZ expression by the reporter
plasmid (Fig. 1A). The 2.9-kbp DNA was
subcloned into segments that contained single ORFs. When these plasmids
were transfected, D10 was as inhibitory as the fragment
containing all three ORFs whereas D9 and D11 had lesser effects (Fig.
1A). Similar results were obtained when the reporter gene was
regulated by the intermediate P30/300 (2) promoter (Fig.
1B). As a control, frameshift insertion mutations were made by
cleaving the D10 and D9 genes at unique HpaI and
EcoRV sites, respectively, and ligating an 8-mer
EcoRI oligonucleotide linker. Plasmids containing
frameshifted D10 or D9 ORFs did not inhibit late or intermediate
promoter-regulated gene expression (data not shown). The effects
of D10 on early promoters was not evaluated because genes regulated by
early promoters are poorly expressed in transfection assays
(10).
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FIG. 1.
Repression of reporter gene expression by cotransfected
plasmids. Human 293 cells (106) were infected with 10 PFU
of vaccinia virus per cell and transfected 1 h later with calcium
phosphate precipitates containing 2 µg of p11X (A) or p30/300 (B)
and 5 µg of pUC19 or derivatives containing vaccinia virus DNA. After
18 h, lysates were prepared from duplicate wells and assayed for
-galactosidase activity (22). The -galactosidase
activities obtained with the pUC19 vector and p11X or p30/300 were
assigned the value of 100%. The percentage of that activity obtained
by transfections with the other plasmids were determined, and the mean
values from two separate experiments are shown. p11X,
lacZ gene under control of late P11 promoter; p30/300,
lacZ gene under control of G8R intermediate promoter; D*,
2.9-kbp BamHI fragment containing the D9, D10, and D11 ORFs;
D9, BamHI/BglII fragment containing the D9 ORF;
D10, SpeI/RsaI fragment containing the D10 ORF;
D11, BglII/BamHI fragment containing the D11
ORF.
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In the experiments described above, the transfected D10 and D9 genes
were regulated by their natural promoters. Niles and
coworkers
(
24-26) had reported that the D9 and D10 genes have early
and late promoters, respectively. The difference in promoter type,
and
presumably level of expression, may have affected the relative
activities of these genes in transfection assays. We therefore
cloned
the D9 and D10 ORFs into the plasmid vector, pVOTE.2, which
contains
the bacteriophage T7 promoter and an encephalomyocarditis
(EMC)
virus leader that provides enhanced cap-independent translation
(
13,
38). The resulting plasmids were called pVOTE.2/D9 and
pVOTE.2/D10. To provide T7 RNA polymerase, we used vaccinia
virus
vTF7-3, which has the bacteriophage T7 RNA polymerase gene
regulated
by the vaccinia virus early-late P7.5 promoter
(
15). Cells were
infected with vTF7-3 and then transfected
with the late reporter
plasmid and either the control pVOTE.2 vector,
pVOTE.2/D10, or
pVOTE.2/D9 plasmid. We found that D10 severely
inhibited expression
of the reporter gene regulated by either the late
(Fig.
2A) or
intermediate (Fig.
2B)
promoter.
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FIG. 2.
Effects of promoters and EMC leader sequences on
repression of reporter gene expression. The D9 and D10 ORFs, with
NdeI and XhoI restriction endonuclease sites,
were directionally cloned into the pVOTE.2 expression vector
(43) to form pVOTE.2/D9 and pVOTE.2/D10, respectively.
BS-C-1 cells in six-well dishes were infected with vTF7-3
(15) at a multiplicity of infection of 10 PFU/cell and
transfected 1 h later with DOTAP (Boehringer Mannheim) containing
2.5 µg of reporter plasmid and 2.5 µg of pVOTE.2, pVOTE.2/D9, or
pVOTE.2/D10 per well. Extracts, prepared 24 h after transfection,
were analyzed by using a -galactosidase enzyme assay (Promega) and a
SpectraMax 250 microplate spectrophotometer (Molecular Devices
Corporation) set at A420. A minimum of two
concentrations of extract were used to ensure linearity. Transfections
were performed in duplicate and repeated a minimum of three times.
Duplicates from a typical experiment are shown. The promoter type
(late, intermediate, T7, or T7-EMC) used for regulation of the
-galactosidase expression is indicated above each panel.
OD420, optical density at 420 nm.
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Specificity of inhibition.
To evaluate the specificity of the
inhibitory effect for vaccinia virus promoters, two lacZ
reporter plasmids with bacteriophage T7 promoters were employed:
pT7lacZ and pT7EMClacZ. As implied by its name, the latter contains a
cDNA copy of the EMC leader to provide cap-independent translation
(14). D10 inhibited expression by pT7lacZ, indicating that
the effect was not specific for vaccinia virus promoters (Fig. 2C).
Remarkably, reporter gene expression mediated by the T7 promoter and
EMC leader was not inhibited (Fig. 2D), suggesting that capped mRNAs or
cap-dependent translation is the target of the D10 product and
excluding the possibility of nonspecific metabolic or other antiviral effects.
Construction of recombinant vaccinia viruses that inducibly
overexpress the D10 or D9 genes.
To compare the effects of the D10
and D9 proteins on viral gene expression, we constructed vaccinia
viruses with an inducible T7 RNA polymerase gene and an extra copy of
the D9 or D10 ORF under an inducible T7 promoter and EMC virus leader.
By employing the EMC virus leader, we sought to prevent negative
autoregulation of D10 or D9 expression. This VOTE system was originally
developed to inducibly express heterologous recombinant genes
(43) but has been successfully employed to regulate vaccinia
virus genes as well (18, 46). The pVOTE.2/D10 and
pVOTE.2/D9 plasmids were transfected into cells that had been
infected with vT7lacOI, a vaccinia virus that expresses the E. coli lac repressor and an inducible copy of the T7 RNA polymerase
(43), and recombinant viruses vT7lacOI/D10 and vT7lacOI/D9
were isolated by antibiotic selection and plaque purified several times
in succession. The presence of the original D10 or D9 gene, as well as
the inducible copy, was verified by PCR and Southern blotting (data not shown).
Inducible overexpression of the D10 and D9 genes at 20 h
after infection was demonstrated by Western blotting with
rabbit
polyclonal antiserum made to the C-terminal peptide
(CYYESLKKLTEDD)
of D10 and to the N-terminal peptide (MGITMDEEVIFETPRC)
of D9.
The amounts of D10 and D9 made by the parental vT7lacOI or by
the recombinant viruses in the absence of inducer were below the
level of detection with these antibodies. However, prominent D10
(Fig.
3A) and D9 (Fig.
3B) bands were
visualized from extracts
of infected cells that had been induced with
IPTG (isopropyl-
-
D-thiogalactopyranoside).
Preimmune serum, from one of the two rabbits used for peptide
immunization, reacted with an unidentified protein with a higher
molecular weight than that of D10 in the lysates of all infected
cells
(Fig.
3A).
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FIG. 3.
Inducible expression of D9 or D10 by recombinant
vaccinia viruses. BS-C-1 cells in six-well dishes were mock infected or
infected with 10 PFU of vT7lacOI per cell and 10 PFU of vT7lacOI/D10
(A) or vT7lacOI/D9 (B) per cell in the presence or absence of 100 µM
IPTG. The infected cells were harvested at 22 h and lysed in 62.5 mM Tris-HCl (pH 6.8)-12.5% glycerol-1.25% sodium dodecyl
sulfate-0.001% bromophenol blue-1.5% -mercaptoethanol. The
viscosity of the extracts was reduced by passage through a 25-gauge
needle, and the material was applied to a 12.5% polyacrylamide gel.
After electrophoresis, the proteins were transferred to a
nitrocellulose membrane (Micron, Inc.) and incubated with preimmune or
anti-D10 or anti-D9 rabbit serum as indicated. Western blots were
developed with a BCIP-NBT
(5-bromo-4-chloro-3-indolylphosphate-nitroblue tetrazolium)
phosphatase substrate (Kirkegaard & Perry Laboratories Inc.). Standard
markers are shown on the left of each blot, with masses in kilodaltons.
The arrows point to the D10 and D9 bands.
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Effects of D10 overexpression on virus replication.
The sizes
of plaques formed by vT7lacOI/D10 were moderately reduced with 50 µg
of IPTG per ml and severely reduced at 250 µg/ml (Fig.
4), suggesting that large amounts of the
D10 gene product had a negative effect on virus replication. In
contrast, the sizes of vT7lacOI and vT7lacOI/D9 plaques were unaffected by inducer (Fig. 4). The selective effect of IPTG on replication of
vT7lacOI/D10 was confirmed under single-step growth conditions (Fig.
5). In this experiment, we included
recombinant virus vGW3 which contains the lacZ gene under
control of the inducible T7 promoter and EMC virus leader
(43).
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FIG. 4.
Effect of D10 overexpression on plaque formation. BS-C-1
cells were inoculated with vT7/lacOI, vT7/lacOI/D10, or vT7/lacOI/D9 in
the presence of 0, 50, or 250 µM IPTG. The cells were stained with
crystal violet after 2 days (13).
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FIG. 5.
Effect of D10 overexpression on virus yield. BS-C-1
cells were inoculated with 5 PFU of vT7lacoI/D10 (I/D10), vT7lacOI/D9
(I/D9), or vGW3 per cell in the presence (solid lines) or absence
(broken lines) of IPTG. At the indicated times, the infected cells were
harvested and the plaque titers were determined in duplicate on BS-C-1
cells in the absence of IPTG. Mean values were plotted.
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Effects of D10 and D9 overexpression on viral protein
synthesis.
Cells were infected in the presence or absence of IPTG
and pulse-labeled with [35S]methionine at various times
to determine the effects of D10 and D9 expression on viral protein
synthesis. Overexpression of D10 severely inhibited viral protein
synthesis at 12 and 20 h after infection, whereas D9 inhibited
protein synthesis only at the later time (Fig.
6), which probably accounts for the lack of effect of D9 overexpression on virus replication (Fig. 4 and 5). The
D10 and D9 bands were difficult to resolve by pulse-labeling because of
comigration of other viral proteins. However, bands of the expected
sizes appeared to have a greater intensity, relative to that of
proteins of other sizes, in the presence of IPTG than in its absence.
In contrast, the -galactosidase band induced by vGW3 (43)
was readily discerned and there was little effect on the synthesis of
viral proteins, excluding the possibility of nonspecific effects due to
overexpression of any protein in this system (Fig. 6).
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FIG. 6.
Effects of D10 or D9 overexpression on viral protein
synthesis. BS-C-1 cells in six-well dishes were infected with 5 PFU of
vGW3, vT7lacOI/D10, or vT7lacOI/D9 per cell in the presence (+) or
absence ( ) of 250 µM IPTG. At the indicated hours postinfection
(hpi), the cells were incubated for 30 min in methionine-free medium
and then incubated for 30 min with 50 µCi of
[35S]methionine and harvested. The lysates were analyzed
by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and
autoradiography. -Galactosidase (Beta Gal.) could be seen as a
distinct band in the IPTG-containing lanes and is indicated by an
arrow. The D10 and D9 bands could not be resolved, but their
approximate positions based on Western blots (Fig. 3) are indicated by
arrows. The positions of standard markers with masses in
kilodaltons are shown on the left.
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Effects of D10 and D9 on steady-state levels of late mRNA.
RNase protection assays were performed to determine the effects of the
D10 and D9 proteins on the steady-state levels of a late mRNA. The
transcript of the F17 gene, encoding the 11,000-molecular-weight structural protein, has been well characterized and used in previous studies as a representative late mRNA (3, 5, 36, 45). BS-C-1
cells infected with vGW3 served as a control. The 682-nucleotide biotinylated RNA probe extended from 556 to +126, relative to the RNA
start site at +1. A properly initiated 126-nucleotide RNase-protected
band as well as some undigested full-length probe was detected at 12 and 20 h after infection with vGW3; the addition of IPTG had
little or no effect (Fig. 7). In cells
infected with vT7lacOI/D9, IPTG induced a moderate reduction in the
amount of the RNase-protected band at 12 h and a severe reduction
at 20 h (Fig. 7). In cells infected with vT7lacOI/D10, IPTG caused
a severe reduction at both 12 and 20 h (Fig. 7). The reductions in
the amounts of the late mRNA corresponded to the effects on viral
protein synthesis and replication shown in the previous sections.
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FIG. 7.
Effect of D10 and D9 overexpression on viral RNA. BS-C-1
cells were infected as described in the legend to Fig. 6. Infected
cells were harvested after 12 or 20 h by using a Direct Protect
Lysate RPA kit (Ambion Inc.). A 682-nucleotide biotinylated RNA probe
complementary to sequences upstream and downstream of the start site of
the F17R transcript encoding the 11,000-molecular-weight protein was
made in vitro by using the BrightStar Biotinscript kit (Ambion Inc.).
The lysate (49 µl) was hybridized with an excess of the probe (0.2 to
1 ng) overnight at 37°C. RNase T1 and A were used to digest
unhybridized RNA and then were inactivated by treatment with 10%
Sarkosyl and proteinase K. The remaining RNA was precipitated with
isopropanol and separated on an 8 M urea-6% polyacrylamide
denaturing gel. The RNA was transferred to a BrightStar-Plus positively
charged nylon membrane (Ambion Inc.) and immobilized by UV
cross-linking. The RNA was detected by using the Ambion BrightStar
BioDetect nonisotopic detection kit. The 682- and 126-nucleotide
biotinylated RNA species are indicated by arrows. The numbers on the
left refer to molecular size standards in nucleotides.
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Conclusions.
A transfection approach, successfully used to
identify the ORFs encoding activators of vaccinia virus late gene
expression (22), has led us to an ORF that decreases gene
expression. The inhibitory effect of D10 was abrogated by interrupting
its reading frame, indicating that the protein product was required for
activity. The inhibitory effect of D10 was manifested regardless of
whether an intermediate or late vaccinia virus promoter or a
bacteriophage T7 promoter was used for the reporter gene, indicating
that the mechanism did not involve promoter sequence recognition. The
specificity of the mechanism was demonstrated by using a reporter gene
with an EMC virus leader sequence which allows cap-independent
translation. In this case, expression was resistant to D10, thereby
excluding indirect metabolic effects. Further studies demonstrated that the inducible overexpression of D10, and to a lesser extent D9, by
recombinant vaccinia viruses inhibited viral gene expression. No such
effect occurred when cells were infected with a similarly constructed
recombinant virus expressing -galactosidase, which excludes
nonspecific effects of protein overexpression. The inhibition mediated
by D10 correlated with decreases in the steady-state concentrations of
a representative late mRNA.
Global alignments indicated that the vaccinia virus D10 and D9 proteins
are 25% identical to each other and highly conserved
among other
poxviruses. Homologues are present in variola virus
(
27,
39), fowlpox virus (
7), Shope fibroma virus
(
40),
and molluscum contagiosum virus (
38). The
inability to isolate
infectious D10 deletion mutants of fowlpox virus
(
7) or vaccinia
virus (
39a) is consistent
with an essential function. By contrast,
the neighboring D9 gene was
deleted from both fowlpox virus (
7)
and vaccinia virus
(
39a) without abrogating infectivity. If D9
and D10 have
overlapping functions, as suggested by their sequence
similarity, D10
may be able to compensate for the absence of D9
but not vice versa.
Although we succeeded in deleting the original
D10 gene from
vT7lacOI/D10, replication still occurred in the
absence of IPTG,
suggesting insufficiently stringent repression
of the T7
promoter-controlled D10 gene and a requirement for only
very small
amounts of the D10 product (
39a).
The finding of MutF motifs within both the D9 and D10 genes
(
23) provides a possible clue to their function and a
direction
for further research. This amino acid signature was
originally
identified as an important functional region of the
E. coli MutT
and the
Streptococcus
pneumoniae MutX antimutator proteins (
28).
Subsequent
computer searches revealed a 20- to 30-amino-acid sequence
with 6 to 10 positions that have highly conserved amino acids
in a variety of
proteins encoded by eubacteria, eukaryotes, and
members of two virus
families, poxviruses and African swine fever
virus (
6,
23).
The characterized nonviral proteins in this
family have widely
differing functions due to their ability to
hydrolyze a nucleoside
diphosphate linked to some moiety, such
as nucleoside triphosphates,
coenzymes, nucleotide sugars, and
dinucleoside polyphosphates. Since
the cap structure of mRNA is
a dinucleoside triphosphate (
16,
44), our finding that cap-independent
reporter gene expression
was not inhibited by the D10 product
is intriguing. The D10 protein
might bind to or hydrolyze cap
structures and thereby affect the
stability or translatability
of mRNAs. The decreased amounts of late
vaccinia virus mRNA detected
when D10 was overexpressed could be a
direct consequence of D10
activity or secondary to a translational
effect on the synthesis
of other viral or cellular
proteins.
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ACKNOWLEDGMENTS |
We thank Joe Baldick for carrying out preliminary transfection and
RNA analysis experiments.
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FOOTNOTES |
*
Corresponding author. Mailing address: Building 4, Room
229, 4 Center Dr., MSC 0445, National Institutes of Health, Bethesda, MD 20892-0445. Phone: (301) 496-9869. Fax: (301) 480-1147. E-mail: bmoss{at}nih.gov.
Present address: Department of Biology and Microbiology, University
of Wisconsin Oshkosh, Oshkosh, WI 54901-8640.
Present address: Strata Biosciences, Alameda, CA 94501.
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REFERENCES |
| 1.
|
Ahn, B.-Y., and B. Moss.
1992.
RNA polymerase-associated transcription specificity factor encoded by vaccinia virus.
Proc. Natl. Acad. Sci. USA
89:3536-3540[Abstract/Free Full Text].
|
| 2.
|
Baldick, C. J.,
J. G. Keck, and B. Moss.
1992.
Mutational analysis of the core, spacer and initiator regions of vaccinia virus intermediate class promoters.
J. Virol.
66:4710-4719[Abstract/Free Full Text].
|
| 3.
|
Baldick, C. J., Jr., and B. Moss.
1993.
Characterization and temporal regulation of mRNAs encoded by vaccinia virus intermediate-stage genes.
J. Virol.
67:3515-3527[Abstract/Free Full Text].
|
| 4.
|
Bertholet, C.,
R. Drillien, and R. Wittek.
1985.
One hundred base pairs of 5' flanking sequence of a vaccinia virus late gene are sufficient to temporally regulate late transcription.
Proc. Natl. Acad. Sci. USA
82:2096-2100[Abstract/Free Full Text].
|
| 5.
|
Bertholet, C.,
E. Van Meir,
B. ten Heggeler-Bordier, and R. Wittek.
1987.
Vaccinia virus produces late mRNAs by discontinuous synthesis.
Cell
50:153-162[Medline].
|
| 6.
|
Bessman, M. J.,
D. N. Frick, and S. F. O'Handley.
1996.
The MutT proteins or "Nudix" hydrolases, a family of versatile, widely distributed, "housecleaning" enzymes.
J. Biol. Chem.
271:25059-25062[Free Full Text].
|
| 7.
|
Binns, M. M.,
B. S. Britton,
C. Mason, and M. E. G. Boursnell.
1990.
Analysis of the fowlpox virus genome region corresponding to the vaccinia virus D6 to A1 regionlocation of, and variation in, non-essential genes in poxviruses.
J. Gen. Virol.
71:2873-2881[Abstract/Free Full Text].
|
| 8.
|
Broyles, S. S., and B. S. Fesler.
1990.
Vaccinia virus gene encoding a component of the viral early transcription factor.
J. Virol.
64:1523-1529[Abstract/Free Full Text].
|
| 9.
|
Broyles, S. S.,
L. Yuen,
S. Shuman, and B. Moss.
1988.
Purification of a factor required for transcription of vaccinia virus early genes.
J. Biol. Chem.
263:10754-10760[Abstract/Free Full Text].
|
| 10.
|
Cochran, M. A.,
M. Mackett, and B. Moss.
1985.
Eukaryotic transient expression system dependent on transcription factors and regulatory DNA sequences of vaccinia virus.
Proc. Natl. Acad. Sci. USA
82:19-23[Abstract/Free Full Text].
|
| 11.
|
Davison, A. J., and B. Moss.
1989.
The structure of vaccinia virus early promoters.
J. Mol. Biol.
210:749-769[Medline].
|
| 12.
|
Davison, A. J., and B. Moss.
1989.
The structure of vaccinia virus late promoters.
J. Mol. Biol.
210:771-784[Medline].
|
| 13.
|
Earl, P. L.,
N. Cooper, and B. Moss.
1991.
Preparation of cell cultures and vaccinia virus stocks, p. 16.16.1-16.16.7.
In
F. M. Ausubel, R. Brent, R. E. Kingston, D. D. Moore, J. G. Seidman, J. A. Smith, and K. Struhl (ed.), Current protocols in molecular biology, vol. 2. Greene Publishing Associates & Wiley Interscience, New York, N.Y.
|
| 14.
|
Elroy-Stein, O.,
T. R. Fuerst, and B. Moss.
1989.
Cap-independent translation of mRNA conferred by encephalomyocarditis virus 5' sequence improves the performance of the vaccinia virus/bacteriophage T7 hybrid expression system.
Proc. Natl. Acad. Sci. USA
86:6126-6130[Abstract/Free Full Text].
|
| 15.
|
Fuerst, T. R.,
E. G. Niles,
F. W. Studier, and B. Moss.
1986.
Eukaryotic transient-expression system based on recombinant vaccinia virus that synthesizes bacteriophage T7 RNA polymerase.
Proc. Natl. Acad. Sci. USA
83:8122-8126[Abstract/Free Full Text].
|
| 16.
|
Furuichi, Y.,
S. Muthukrishnan, and A. J. Shatkin.
1975.
5'-Terminal m-7G(5')ppp(5')G-m-p in vivo: identification in reovirus genome RNA.
Proc. Natl. Acad. Sci. USA
72:742-745[Abstract/Free Full Text].
|
| 17.
|
Gershon, P. D., and B. Moss.
1990.
Early transcription factor subunits are encoded by vaccinia virus late genes.
Proc. Natl. Acad. Sci. USA
87:4401-4405[Abstract/Free Full Text].
|
| 18.
|
Hu, X.,
L. J. Carroll,
E. J. Wolffe, and B. Moss.
1996.
De novo synthesis of the early transcription factor 70-kDa subunit is required for morphogenesis of vaccinia virions.
J. Virol.
70:7669-7677[Abstract].
|
| 19.
|
Hubbs, A. E., and C. F. Wright.
1996.
The A2L intermediate gene product is required for in vitro transcription from a vaccinia virus late promoter.
J. Virol.
70:327-331[Abstract].
|
| 20.
|
Johnson, G. P.,
S. J. Goebel, and E. Paoletti.
1993.
An update on the vaccinia virus genome.
Virology
196:381-401[Medline].
|
| 21.
|
Kates, J. R., and B. R. McAuslan.
1967.
Poxvirus DNA-dependent RNA polymerase.
Proc. Natl. Acad. Sci. USA
58:134-141[Free Full Text].
|
| 22.
|
Keck, J. G.,
C. J. Baldick, and B. Moss.
1990.
Role of DNA replication in vaccinia virus gene expression: a naked template is required for transcription of three late transactivator genes.
Cell
61:801-809[Medline].
|
| 23.
|
Koonin, E. V.
1993.
A highly conserved sequence motif defining the family of MutT-related proteins from eubacteria, eukaryotes and viruses.
Nucleic Acids Res.
21:4847[Free Full Text].
|
| 24.
|
Lee-Chen, G. J.,
N. Bourgeois,
K. Davidson,
R. C. Condit, and E. G. Niles.
1988.
Structure of the transcription initiation and termination sequences of seven early genes in the vaccinia virus HindIII D fragment.
Virology
163:64-79[Medline].
|
| 25.
|
Lee-Chen, G. J., and E. G. Niles.
1988.
Map positions of the 5' ends of eight mRNAs synthesized from the late genes in the vaccinia virus HindIII D fragment.
Virology
163:80-92[Medline].
|
| 26.
|
Lee-Chen, G. J., and E. G. Niles.
1988.
Transcription and translation mapping of the 13 genes in the vaccinia virus HindIII D fragment.
Virology
163:52-63[Medline].
|
| 27.
|
Massung, R. F.,
L.-I. Liu,
J. Qi,
J. C. Knight,
T. E. Yuran,
A. R. Kerlavage,
J. M. Parsons,
J. C. Venter, and J. Esposito.
1994.
Analysis of the complete genome of smallpox Variola major virus strain Bangladesh-1975.
Virology
201:215-240[Medline].
|
| 28.
|
Méjean, V.,
C. Salles,
L. C. Bullions,
M. J. Bessman, and J.-P. Claverys.
1994.
Characterization of the mutX gene of Streptococcus pneumoniae as a homologue of Escherichia coli mutT, and tentative definition of a catalytic domain of the dGTP pyrophosphohydrolases.
Mol. Microbiol.
11:323-330[Medline].
|
| 29.
|
Moss, B., and N. P. Salzman.
1968.
Sequential protein synthesis following vaccinia virus infection.
J. Virol.
2:1016-1027[Abstract/Free Full Text].
|
| 30.
|
Munyon, W. E.,
E. Paoletti, and J. T. Grace, Jr.
1967.
RNA polymerase activity in purified infectious vaccinia virus.
Proc. Natl. Acad. Sci. USA
58:2280-2288[Free Full Text].
|
| 31.
|
Oda, K., and W. K. Joklik.
1967.
Hybridization and sedimentation studies on "early" and "late" vaccinia messenger RNA.
J. Mol. Biol.
27:395-419[Medline].
|
| 32.
|
Passarelli, A. L.,
G. R. Kovacs, and B. Moss.
1996.
Transcription of a vaccinia virus late promoter template: requirement for the product of the A2L intermediate-stage gene.
J. Virol.
70:4444-4450[Abstract].
|
| 33.
|
Pennington, T. H.
1974.
Vaccinia virus polypeptide synthesis: sequential appearance and stability of pre- and post-replicative polypeptides.
J. Gen. Virol.
25:433-444[Abstract/Free Full Text].
|
| 34.
|
Rosales, R.,
N. Harris,
B.-Y. Ahn, and B. Moss.
1994.
Purification and identification of a vaccinia virus-encoded intermediate stage promoter-specific transcription factor that has homology to eukaryotic transcription factor SII (TFIIS) and an additional role as a viral RNA polymerase subunit.
J. Biol. Chem.
269:14260-14267[Abstract/Free Full Text].
|
| 35.
|
Sanz, P., and B. Moss.
1998.
A new vaccinia virus intermediate transcription factor.
J. Virol.
72:6880-6883[Abstract/Free Full Text].
|
| 36.
|
Schwer, B.,
P. Visca,
J. C. Vos, and H. G. Stunnenberg.
1987.
Discontinuous transcription or RNA processing of vaccinia virus late messengers results in a 5' poly(A) leader.
Cell
50:163-169[Medline].
|
| 37.
|
Sebring, E. D., and N. P. Salzman.
1967.
Metabolic properties of early and late vaccinia messenger ribonucleic acid.
J. Virol.
1:550-575[Abstract/Free Full Text].
|
| 38.
|
Senkevich, T. G.,
E. V. Koonin,
J. J. Bugert,
G. Darai, and B. Moss.
1997.
The genome of molluscum contagiosum virus: analysis and comparison with other poxviruses.
Virology
233:19-42[Medline].
|
| 39.
|
Shchelkunov, S. N.,
V. M. Blinov,
A. V. Totmenin,
S. S. Marennikova,
A. A. Kolykhalov,
I. V. Frolov,
V. E. Chizhikov,
V. V. Gytorov,
P. V. Gashikov,
E. F. Belanov,
P. A. Belavin,
S. M. Resenchuk,
O. G. Andzhaparidze, and L. S. Sandakhchiev.
1993.
Nucleotide sequence analysis of variola virus HindIII M,L, I genome fragments.
Virus Res.
27:25-35[Medline].
|
| 39a.
| Shors, T., and B. Moss. Unpublished data.
|
| 40.
|
Strayer, D. S.,
H. H. Jerng, and K. Oconnor.
1991.
Sequence and analysis of a portion of the genomes of Shope fibroma virus and malignant rabbit fibroma virus that is important for viral replication in lymphocytes.
Virology
185:585-595[Medline].
|
| 41.
|
Vos, J. C.,
M. Sasker, and H. G. Stunnenberg.
1991.
Promoter melting by a stage-specific vaccinia virus transcription factor is independent of the presence of RNA polymerase.
Cell
65:105-114[Medline].
|
| 42.
|
Vos, J. C.,
M. Sasker, and H. G. Stunnenberg.
1991.
Vaccinia virus capping enzyme is a transcription initiation factor.
EMBO J.
10:2553-2558[Medline].
|
| 43.
|
Ward, G. A.,
C. K. Stover,
B. Moss, and T. R. Fuerst.
1995.
Stringent chemical and thermal regulation of recombinant gene expression by vaccinia virus vectors in mammalian cells.
Proc. Natl. Acad. Sci. USA
92:6773-6777[Abstract/Free Full Text].
|
| 44.
|
Wei, C. M., and B. Moss.
1975.
Methylated nucleotides block 5'-terminus of vaccinia virus mRNA.
Proc. Natl. Acad. Sci. USA
72:318-322[Abstract/Free Full Text].
|
| 45.
|
Wittek, R.,
M. Hanggi, and G. Hiller.
1984.
Mapping of a gene coding for a major late structural polypeptide on the vaccinia virus genome.
J. Virol.
49:371-378[Abstract/Free Full Text].
|
| 46.
|
Wolffe, E. J.,
D. M. Moore,
P. J. Peters, and B. Moss.
1996.
Vaccinia virus A17L open reading frame encodes an essential component of nascent viral membranes that is required to initiate morphogenesis.
J. Virol.
70:2797-2808[Abstract].
|
| 47.
|
Wright, C. F.,
J. G. Keck, and B. Moss.
1991.
A transcription factor for expression of vaccinia virus late genes is encoded by an intermediate gene.
J. Virol.
65:3715-3720[Abstract/Free Full Text].
|
Journal of Virology, January 1999, p. 791-796, Vol. 73, No. 1
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
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