title: Transient expression analysis of the reticuloendotheliosis virus long terminal repeat element.
abstract: A region of the Reticuloendotheliosis virus (REV) long terminal repeat (LTR) harbouring single or duplicated copies of 46-bp and 26-bp sequence elements is implicated in enhancer activity. Sequences residing upstream from the proviral 3' LTR did not contribute to activity of the intact LTR. Gene expression regulated by a combination of REV enhancer and SV40 early region promoter was 50-fold less than from the analogous construct containing the chicken syncytial virus promoter. Deletion of LTR sequences immediately downstream of the CAP site, which include a region capable of forming a stable hairpin in the mRNA, decreased expression by 70%. Expression assays and S1 nuclease mapping showed that a second transcriptional start site, identified by transcription in vitro using HeLa cell lysates and purified DNA templates, was not used in vivo in the cell lines examined.
authors.affiliation: Cancer Research Laboratory, University of Western Ontario, London, Canada.
authors.forename: A A
authors.initials: AA
authors.lastname: Ridgway
authors.forename: H J
authors.initials: HJ
authors.lastname: Kung
authors.forename: D J
authors.initials: DJ
authors.lastname: Fujita
mesh_terms: D001667:Binding, Competitive; D004252:DNA Mutational Analysis; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D066298:In Vitro Techniques; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000648:ultrastructure; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D001356:Reticuloendotheliosis virus / Q000235:genetics*; D012190:Retroviridae / Q000235:genetics*; D014157:Transcription Factors / Q000502:physiology; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D012333:RNA, Messenger; D014157:Transcription Factors