Document 0402
 DOCN  M9620402
 TI    p6Gag is required for particle production from full-length human
       immunodeficiency virus type 1 molecular clones expressing protease.
 DT    9602
 AU    Huang M; Orenstein JM; Martin MA; Freed EO; Laboratory of Molecular
       Microbiology, National Institute of; Allergy and Infectious Diseases,
       NIH, Bethesda, MD 20892-0460,; USA.
 SO    J Virol. 1995 Nov;69(11):6810-8. Unique Identifier : AIDSLINE
       MED/96013776
 AB    The human immunodeficiency virus type 1 (HIV-1) Gag protein precursor,
       Pr55Gag, contains at its C-terminal end a proline-rich, 6-kDa domain
       designated p6. Two functions have been proposed for p6: incorporation of
       the HIV-1 accessory protein Vpr into virus particles and virus particle
       production. To characterize the role of p6 in the HIV-1 life cycle and
       to map functional domains within p6, we introduced a number of nonsense
       and single and multiple amino acid substitution mutations into p6.
       Following the introduction of the mutations into the full-length HIV-1
       molecular clone pNL4-3, the effects on Gag protein expression and
       processing, virus particle production, and virus infectivity were
       analyzed. The production of mutant virus particles was also examined by
       transmission electron microscopy. The results indicate that (i) p6 is
       required for efficient virus particle production from a full-length
       HIV-1 molecular clone; (ii) a Pro-Thr-Ala-Pro sequence, located between
       residues 7 and 10 of p6, is critical for virus particle production;
       (iii) mutations outside the Pro-Thr-Ala-Pro motif have little or no
       effect on virus assembly and release; (iv) the p6 defect is manifested
       at a late stage in the budding process; and (v) mutations in p6 that
       severely reduce virion production in HeLa cells also block or
       significantly delay the establishment of a productive infection in the
       CEM (12D-7) T-cell line. We further demonstrate that mutational
       inactivation of the viral protease reverses the p6 defect, suggesting a
       functional linkage between p6 and the proteolytic processing of the Gag
       precursor protein during the budding of progeny virions.
 DE    Amino Acid Sequence  Capsid/BIOSYNTHESIS  Cell Line  Cloning, Molecular
       Gene Products, gag/BIOSYNTHESIS/*METABOLISM  Gene Products,
       vpr/METABOLISM  Genes, pol  Hela Cells  Human  HIV
       Protease/*BIOSYNTHESIS  HIV-1/ENZYMOLOGY/*PHYSIOLOGY/ULTRASTRUCTURE
       Kinetics  Microscopy, Electron  Molecular Sequence Data  Mutagenesis,
       Site-Directed  Point Mutation  Recombinant Proteins/METABOLISM  Time
       Factors  Transfection  *Virus Replication  JOURNAL ARTICLE

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