       Document 0628
 DOCN  M9630628
 TI    Two strong 5' splice sites and competing, suboptimal 3' splice sites
       involved in alternative splicing of human immunodeficiency virus type 1
       RNA.
 DT    9603
 AU    O'Reilly MM; McNally MT; Beemon KL; Department of Biology, Johns Hopkins
       University, Baltimore,; Maryland 21218, USA.
 SO    Virology. 1995 Nov 10;213(2):373-85. Unique Identifier : AIDSLINE
       MED/96074513
 AB    The human immunodeficiency virus type 1 (HIV-1) genome contains 20 exons
       that are alternatively spliced from 16 splice sites to generate more
       than 40 different mRNAs, including incompletely spliced and unspliced
       mRNAs. In contrast to avian retroviral RNA, which has a cis-acting
       element in gag that negatively regulates splicing (NRS), HIV-1 RNA did
       not have any NRS sequences in the gag or pol genes detectable by a
       splicing inhibition assay. However, this assay demonstrated that the
       HIV-1 first 5' splice site competed with a cellular 5' splice site,
       suggesting that HIV-1 may have some strong splice sites. To extend this
       observation, we used a splice site swapping strategy to determine the
       efficiency of 14 HIV-1 splice sites in human beta globin chimeras tested
       in transient transfection experiments. While the 1st HIV-1 5' splice
       site used in all spliced transcripts and the 4th 5' splice site used in
       most of the 2-kb transcripts were efficient, the other splice sites,
       including all the 3' splice sites, were less efficient, ranging in use
       from 25 to 60%. We propose that this range of splice site efficiencies
       contributes to the regulation of alternative splicing of HIV-1 mRNAs.
 DE    *Alternative Splicing  Base Sequence  Binding Sites  Cell Line,
       Transformed  Exons  Genes, myc  Genetic Engineering  Genome, Viral
       Globin/GENETICS  Human  HIV-1/*GENETICS  Molecular Sequence Data  RNA,
       Messenger/*GENETICS/METABOLISM  RNA, Viral/*GENETICS/METABOLISM
       Support, U.S. Gov't, P.H.S.  Transfection  JOURNAL ARTICLE

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

