title: Transcriptional (p40x) and post-transcriptional (p27x-III) regulators are required for the expression and replication of human T-cell leukemia virus type I genes.
abstract: The pX sequence of human T-cell leukemia virus type I codes for three products: p40x, p27x-III, and p21x-III. p40x is a transcriptional trans-activator that activates not only the viral long terminal repeat but also cellular genes for interleukin 2 and its receptor. p27x-III and p21x-III are not required for transcriptional activation, and their functions were unknown. Cotransfection experiments with defective human T-cell leukemia virus type I proviruses and various pX expression plasmids revealed that p27x-III, in addition to p40x, was required for gag gene expression. Furthermore, it was shown that p27x-III induced accumulation of a high level of unspliced viral gag mRNA. These results indicate that p27x-III is a post-transcriptional modulator of viral RNA whose transcription has been fully activated by p40x.
mesh_terms: D002460:Cell Line; D004261:DNA Replication; D004262:DNA Restriction Enzymes; D017977:Deltaretrovirus / Q000235:genetics*; D005091:Exons; D005809:Genes, Regulator; D005814:Genes, Viral; D006801:Humans; D010957:Plasmids; D012323:RNA Processing, Post-Transcriptional; D014158:Transcription, Genetic; D014162:Transfection; D014779:Virus Replication
chemical_list: D004262:DNA Restriction Enzymes