Previous Article | Next Article ![]()
Journal of Virology, January 1999, p. 234-241, Vol. 73, No. 1
Center for Virology, Immunology, and
Infectious Disease Research, Children's National Medical Center,
Washington, D.C. 20010
Received 19 June 1998/Accepted 29 September 1998
The oncogenic potential of many nonacute retroviruses is dependent
on the duplication of the enhancer sequences present in the unique 3'
(U3) region of the long terminal repeat (LTR). In a molecular clone
(MCF 247-W) of the murine leukemia virus MCF 247, a leukemogenic mink
cell focus-inducing (MCF) virus, the U3 enhancer sequences are tandemly
repeated in the LTR. We mutated the enhancer region of MCF 247-W to
test the hypothesis that the duplicated enhancer sequences of this
virus have a sequence-specific and/or a stereospecific role in enhancer
function required for transformation. In one virus, we inserted 14 nucleotide bp into the novel sequence generated at the junction of the
two enhancers to generate an MCF virus with an interrupted enhancer
region. In the second virus, only one copy of the enhancer sequences
was present. This second virus also lacked the junction sequence
present between the two enhancers of MCF 247-W. Both viruses were less leukemogenic and had a longer mean latency period than MCF 247-W. These
data indicate that the sequence generated at the junction of the two
enhancers and/or the stereospecific arrangement of the two enhancer
elements are required for the full oncogenic potential of MCF 247-W. We
analyzed proviral LTRs within the c-myc locus in tumor DNAs
from mice injected with the MCF virus with the interrupted enhancer
region. Some of the proviral LTRs integrated upstream of
c-myc contain enhancer regions that are larger than those
of the injected virus. These results are consistent with the suggestion
that the virus with an interrupted enhancer changes in vivo to perform
its role in the transformation of T cells.
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Sequence-Specific and/or Stereospecific Constraints
of the U3 Enhancer Elements of MCF 247-W Are Important for
Pathogenicity
*
Corresponding author. Mailing address: Center for
Virology, Immunology, and Infectious Disease Research, Children's
National Medical Center, 111 Michigan Ave., N.W., Washington, D.C.
20010. Phone: (202) 884-3981. Fax: (202) 884-3985. E-mail:
holland{at}gwis2.circ.gwu.edu.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|