J Virol. 1999 Oct;73(10):8112-9. Unique Identifier : AIDSLINE
The human T-cell leukemia virus (HTLV) Rex protein is essential for
efficient expression of the viral structural and enzymatic gene
products. In this study, we assessed the role of the HTLV-2 rex gene in
viral RNA expression and Gag protein production. Following transfection
of human JM4 T cells with wild-type and rex mutant full-length proviral
constructs, PCR was used for semiquantitative analysis of specific viral
RNA transcripts. In the presence of Rex, the total amount of
steady-state viral RNA was increased fourfold. Rex significantly
up-regulated the level of incompletely spliced RNAs by increasing RNA
stability and was associated with a twofold down-regulation of the
completely spliced tax/rex RNA. PCR analysis of subcellular RNA
fractions, isolated from transfected cells, indicated that the level of
gag/pol and env cytoplasmic RNAs were increased 7- to 9-fold in the
presence of Rex, whereas Gag protein production was increased 130-fold.
These data indicate that HTLV-2 Rex increases the stability and promotes
nucleus-to-cytoplasm transport of the incompletely spliced viral RNAs,
ultimately resulting in increased structural protein production.
Moreover, this model system provides a sensitive approach to further
characterize HTLV gene expression from full-length proviral clones
following transfection of human T cells.
JOURNAL ARTICLE B-Lymphocytes/VIROLOGY Biological Transport Cell Line
Cell Nucleus/VIROLOGY Cytoplasm/VIROLOGY Gene Products,
gag/*PHYSIOLOGY Gene Products, pol/*PHYSIOLOGY Gene Products,
rex/*PHYSIOLOGY Human HTLV-II/*PHYSIOLOGY RNA, Viral/*PHYSIOLOGY
Support, Non-U.S. Gov't Support, U.S. Gov't, P.H.S.
T-Lymphocytes/VIROLOGY Viral Envelope Proteins/*PHYSIOLOGY Virus