Document 3295
 DOCN  M94A3295
 TI    Internally initiated gag and gag-pol precursors of HIV-1.
 DT    9412
 AU    Kojima A; Tachibana Y; Hoshikawa N; Kurata T; Department of Pathology,
       National Institute of Health, Tokyo,; Japan.
 SO    Int Conf AIDS. 1994 Aug 7-12;10(1):109 (abstract no. PA0053). Unique
       Identifier : AIDSLINE ICA10/94369280
 AB    OBJECTIVE: Inspection of the gag ORF reveales a second methionin (M2)
       codon which is 10 resides downstream of the p17-p24 junction. Our object
       is to examine the de novo synthesis of internally initiated gag or
       gag-pol precursors. METHODS: Mutant gag or gag-pol ORFs either lacking
       the M2 codon, replaced by a leucine or isoleucine codon, or starting at
       the M2 codon were constructed and expressed by vaccinia viruses. HIV-1
       gag and pol proteins were analysed by western blotting, p24 ELISA and RT
       assay. HIV-1-like particle formation was examined by sucrose density
       centrifugation and electron microscopy. RESULTS AND DISCUSSION: (1)
       Deletion or substitution of the M2 codon abolished the expression of a
       40 kDa gag protein (Pr40gag) with no effects on the processing of
       Pr55gag and Pr160gag-pol precursors. (2) M2-starting gag and gag-pol
       ORFs expressed Pr40gag and Pr140gag-pol which did not generate mature
       p24 nor RT activity. (3) The smaller precursors, Pr40gag and
       Pr140gag-pol, lacked the ability to form HIV-like particles. These
       results show the existence of internally initiated Pr40gag and
       Pr140gag-pol polyprotein precursors. Involvement of the novel precursors
       in the processing, assembling and packaging of the gag/pol proteins will
       be discussed.
 DE    Codon/GENETICS  Fusion Proteins, gag-pol/*BIOSYNTHESIS/GENETICS  Gene
       Products, gag/*BIOSYNTHESIS/GENETICS  Genes, gag  Genes, pol  Human
       HIV-1/GENETICS/*METABOLISM  In Vitro  Methionine/GENETICS  Mutagenesis,
       Site-Directed  Open Reading Frames  Protein
       Precursors/*BIOSYNTHESIS/GENETICS  Protein Processing,
       Post-Translational  Sequence Deletion  Vaccinia Virus/GENETICS  MEETING
       ABSTRACT

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