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Interaction of viral and cellular factors with the HTLV-III LTR target sequences in vitro.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Heisig, V. Benter, Thomas Josephs, Steven F. Sadaie, Mohammad Reza Okamoto, Takashi Gallo, Robert C. Wong-Staal, Flossie |
| Copyright Year | 1987 |
| Abstract | The location of cis-acting regulatory sequences within the long terminal repeat (LTR) of the human T-cell lymphotropic virus type III was determined by eukaryotic cell transfection and chloramphenicol acetyltransferase (CAT) assay or in vitro cell-free transcription. A 160 base pair (bp) region of the LTR at position - 104 to 56 is required for trans-activation (cap site 1). A 24 bp enhancer element (EHE) capable of increasing the rate of transcription, irrespective of orientation, is located between nucleotides -105 to -80. It contains two 10 bp repeats. Three Sp1 binding sites (Sp1 III-I) are located between -78 and -45. A deletion of Sp1 III allowed for limited TATIII response while the presence of a functional enhancer restored the activity in HTLV-III infected cells. Complete loss of transcriptional activity and CAT gene expression could be attributed to the absence of EHE and Sp1 III-I at position -48. However, reinsertion of the enhancer restored accurate initiation but at a decreased level suggesting that the presence of a Sp1 binding site is not a prerequisite for the accurate initiation of transcription but is required for transcriptional activation independent of a promoter. The presence of a negative regulatory element (NRE) has been demonstrated by removal of the 5' part of U3 to position -117. Nucleotide sequences around the cap site and poly (A) site contain a trans-activator response element (TRE) and could be arranged into a unique secondary structure. A deletion of four nucleotides TCTGAGCCTGGGAGCTC causes a loss of three dimer linkage sequence binding. The CAT gene enzyme expression is completely abolished but transcriptional activity remains at reduced level. |
| Starting Page | 66 |
| Ending Page | 74 |
| Page Count | 9 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.science-connections.com/books/moderntrends/trends7/005-Virology/423-Interaction_of_Viral.pdf |
| PubMed reference number | 3481758v1 |
| Volume Number | 31 |
| Journal | Haematology and blood transfusion |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Acyltransferase Base Pairing Binding Sites Chloramphenicol O-Acetyltransferase Cognitive function: initiation Deletion Mutation Enhancer Elements, Genetic Enhancer of transcription Gene Expression HIV Leukemia, B-Cell Long Terminal Repeat Poly A Poly I-C Regulatory Sequences, Nucleic Acid Response Elements Surgical Replantation Terminal Repeat Sequences Trans-Activators Transcription Initiation Transcription, Genetic Transcriptional Activation Uracil Nucleotides genetic linkage |
| Content Type | Text |
| Resource Type | Article |
