title: The 5' leader sequence of mouse mammary tumor virus enhances expression of the envelope and reporter genes.
abstract: Mouse mammary tumor virus (MMTV) is a complex betaretrovirus, which utilizes a Rev-like auxiliary protein Rem to export the unspliced viral RNA from the nucleus. MMTV env mRNA appears to be exported via a distinct, Rem-independent, mechanism. Here, we analysed the effect of an extensively folded region coinciding with the 5' leader sequence on env gene expression. We found that the presence of the 5' leader stimulates expression of the envelope protein. Enhanced Env production was accompanied by increased cytoplasmic levels of env mRNA. The 5' leader promotes nucleocytoplasmic translocation and increases stability of env mRNA. The region responsible for this effect was mapped to the distal part of the 5' leader. Furthermore, the 5' leader inserted in the sense orientation into a heterologous luciferase expression construct increased luciferase activity.
authors: Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria.
authors: Christine
authors: C
authors: Hohenadl
authors: Christian Doppler Laboratory for Gene Therapeutic Vector Development, Vienna, Austria.|Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria.
authors: Walter H
authors: WH
authors: Gunzburg
authors: Austrianova Singapore, Biopolis, Singapore.
authors: Brian
authors: B
authors: Salmons
authors: Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria.
authors: Stanislav
authors: S
authors: Indik
mesh_terms: D020121:5' Untranslated Regions; D021581:Active Transport, Cell Nucleus; D000818:Animals; D002460:Cell Line; D017930:Genes, Reporter; D006801:Humans; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics / Q000502:physiology*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000096:biosynthesis* / Q000235:genetics; D014779:Virus Replication
chemical_list: D020121:5' Untranslated Regions; D012333:RNA, Messenger; D012367:RNA, Viral; D014759:Viral Envelope Proteins