Biomaterial Database

Post-transcriptional regulator (rex) of HTLV-1 initiates expression of viral structural proteins but suppresses expression of regulatory proteins. 1988

M Hidaka, and J Inoue, and M Yoshida, and M Seiki

Department of Viral Oncology, Cancer Institute, Tokyo, Japan.

Gene expression of human T-cell leukemia virus type 1 (HTLV-1) is regulated by two trans-acting factors encoded by the pX region, p40tax and p27tax.p40tax is a transcriptional activator and p27rex is a post-transcriptional regulator. Using full-length viral DNA, we studied the regulatory effects of rex on HTLV-1 gene expression. p27rex is required for expression of both gag and env proteins, increasing the level of their mRNAs. The effect was dependent on the dose of p27rex expression plasmid. In parallel, increased doses of p27rex suppressed the expression of fully spliced pX mRNA, which encodes the regulatory proteins. These two effects of p27rex operated at the post-transcriptional level and were independent of transcriptional regulation. Lowering the level of pX mRNA down-regulates transcription of the proviral genome. These observations demonstrate that rex is a positive post-transcriptional regulator for gag, pol and env protein expression, and acts at the same time as an indirect negative regulator of viral transcription.

UI	MeSH Term	Description	Entries
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D005809	Genes, Regulator	Genes which regulate or circumscribe the activity of other genes; specifically, genes which code for PROTEINS or RNAs which have GENE EXPRESSION REGULATION functions.	Gene, Regulator,Regulator Gene,Regulator Genes,Regulatory Genes,Gene, Regulatory,Genes, Regulatory,Regulatory Gene
D005814	Genes, Viral	The functional hereditary units of VIRUSES.	Viral Genes,Gene, Viral,Viral Gene
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012323	RNA Processing, Post-Transcriptional	Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.	Post-Transcriptional RNA Modification,RNA Processing,Post-Transcriptional RNA Processing,Posttranscriptional RNA Processing,RNA Processing, Post Transcriptional,RNA Processing, Posttranscriptional,Modification, Post-Transcriptional RNA,Modifications, Post-Transcriptional RNA,Post Transcriptional RNA Modification,Post Transcriptional RNA Processing,Post-Transcriptional RNA Modifications,Processing, Posttranscriptional RNA,Processing, RNA,RNA Modification, Post-Transcriptional,RNA Modifications, Post-Transcriptional
D012333	RNA, Messenger	RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.	Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated
D014157	Transcription Factors	Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.	Transcription Factor,Factor, Transcription,Factors, Transcription
D014162	Transfection	The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.	Transfections