       Document 0295
 DOCN  M94A0295
 TI    Evidence that HIV-1 Rev directly promotes the nuclear export of
       unspliced RNA.
 DT    9412
 AU    Fischer U; Meyer S; Teufel M; Heckel C; Luhrmann R; Rautmann G; Institut
       fur Molekularbiologie und Tumorforschung, Marburg,; Germany.
 SO    EMBO J. 1994 Sep 1;13(17):4105-12. Unique Identifier : AIDSLINE
       MED/94357184
 AB    The Rev trans-activator of human immunodeficiency virus type 1 (HIV-1)
       is a protein that regulates the simultaneous appearance in the cytoplasm
       of both spliced and unspliced forms of viral mRNAs from the same viral
       transcripts by way of recognition of a target sequence termed the
       Rev-responsive element (RRE). Whether Rev acts directly on RNA export or
       by inhibition of splicing, or both, is still a matter of debate. We have
       addressed this issue in Xenopus laevis oocytes by microinjecting RNA
       molecules containing RRE along with purified recombinant Rev protein
       into the oocyte nuclei. Adenovirus pre-mRNA containing an RRE in the
       intron was spliced equally well in the absence and presence of Rev
       protein. Only in the presence of Rev was non-spliced pre-mRNA exported
       from the nucleus; more surprisingly, the excised intron lariat
       (containing RRE) was also exported. Furthermore, an RRE-containing mRNA
       molecule that lacked intron sequences was also efficiently exported from
       the nucleus in a Rev-dependent manner. Therefore our results demonstrate
       that Rev can act directly at the level of nuclear export, independent of
       any inhibitory effect that it may exert on the splicing of pre-mRNA.
       Finally, our finding that the Rev mutant M10, shown previously to be
       inactive in human lymphoid cells, was also unable to export
       RRE-containing RNA molecules from oocyte nuclei suggests that one or
       more cellular factors, evolutionarily conserved between humans and
       Xenopus, interact with Rev in both cell systems to promote nuclear RNA
       export.
 DE    Animal  Base Sequence  Biological Transport  Cell Nucleus/*METABOLISM
       Exons/GENETICS  Gene Products, rev/GENETICS/*METABOLISM  Genes,
       Synthetic  HIV-1/*GENETICS  Microinjections  Molecular Sequence Data
       Mutation  Oocytes  Protein Binding  Recombinant Proteins/METABOLISM  RNA
       Precursors/GENETICS/*METABOLISM  *RNA Splicing  RNA-Binding
       Proteins/METABOLISM  Sequence Deletion  Support, Non-U.S. Gov't  Xenopus
       laevis  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

