cis-Acting inhibitory elements within the pol-env region of human T-cell leukemia virus type 1 possibly involved in viral persistence.
AUTOR(ES)
Saiga, A
RESUMO
Human T-cell leukemia virus type 1 (HTLV-1) remains latent throughout the life of the carrier, with cells containing the provirus and viral gene expression efficiently down-regulated. On a molecular level, exactly how viruses are down-regulated in vivo remains unresolved. We described here the possibility that down-regulation results from the presence of inhibitory elements within the gag-env region of the provirus in fresh peripheral blood mononuclear cells from carriers. In vitro experiments then revealed that potent cis-acting inhibitory elements (CIEs) are indeed contained in two discrete fragments from the pol region and weaker ones in the env region. The effect of CIEs is relieved by the HTLV-1 posttranscriptional regulator Rex through binding to the Rex-responsive element (RxRE), suggesting that Rex might interfere with pre-mRNA degradation and/or activate the export of mRNA molecules harboring both of the inhibitory elements and RxRE on the same RNA molecule. Thus, we propose the hypothesis that such functions of CIEs may be involved in HTLV-1 persistence.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=191668Documentos Relacionados
- Two cis-acting elements responsible for posttranscriptional trans-regulation of gene expression of human T-cell leukemia virus type I.
- Location of cis-acting regulatory sequences in the human T-cell leukemia virus type I long terminal repeat.
- Two cis-acting signals control ribosomal frameshift between human T-cell leukemia virus type II gag and pro genes.
- Cis-acting sequences responsible for the transcriptional activation of human T-cell leukemia virus type I constitute a conditional enhancer.
- p21X mRNA is expressed as a singly spliced pX transcript from defective provirus genomes having a partial deletion of the pol-env region in human T-cell leukemia virus type 1-infected cells.