Human T-cell leukemia virus (HTLV) type II Rex protein binds specifically to RNA sequences of the HTLV long terminal repeat but poorly to the human immunodeficiency virus type 1 Rev-responsive element.
AUTOR(ES)
Yip, M T
RESUMO
The human T-cell leukemia viruses (HTLVs) encode a trans-regulatory protein, Rex, which differentially regulates viral gene expression by controlling the cytoplasmic accumulation of viral mRNAs. Because of insufficient amounts of purified protein, biochemical characterization of Rex activity has not previously been performed. Here, utilizing the baculovirus expression system, we purified HTLV type II (HTLV-II) Rex from the cytoplasmic fraction of recombinant baculovirus-infected insect cells by heparin-agarose chromatography. We directly demonstrated that Rex specifically bound HTLV-II 5' long terminal repeat RNA in both gel mobility shift and immunobinding assays. Sequences sufficient for Rex binding were localized to the R-U5 region of the HTLV-II 5' long terminal repeat and correlate with the region required for Rex function. The human immunodeficiency virus type 1 (HIV-1), has an analogous regulatory protein, Rev, which directly binds to and mediates its action through the Rev-responsive element located within the HIV-1 env gene. We demonstrated that HTLV-II Rex rescued an HIV-1JR-CSF Rev-deficient mutant, although inefficiently. This result is consistent with a weak binding activity to the HIV-1 Rev-responsive element under conditions in which it efficiently bound the HTLV-II long terminal repeat RNA.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=240575Documentos Relacionados
- Human immunodeficiency virus type 1 Rev-responsive element RNA binds to host cell-specific proteins.
- Different sites of interaction for Rev, Tev, and Rex proteins within the Rev-responsive element of human immunodeficiency virus type 1.
- Inhibition of Rev activity and human immunodeficiency virus type 1 replication by antisense oligodeoxynucleotide phosphorothioate analogs directed against the Rev-responsive element.
- The type I human T-cell leukemia virus (HTLV-I) Rex trans-activator binds directly to the HTLV-I Rex and the type 1 human immunodeficiency virus Rev RNA response elements.
- The rev-responsive element negatively regulates human immunodeficiency virus type 1 env mRNA expression in primate cells.
