       Document 0531
 DOCN  M9630531
 TI    Both the changes of six amino acids and the C-terminal truncation caused
       by a one-base insertion in the defective env gene of Friend spleen
       focus-forming virus significantly affect the pathogenic activity of the
       encoded leukemogenic membrane glycoprotein (gp55).
 DT    9603
 AU    Watanabe N; Yugawa T; Ikawa Y; Amanuma H; Laboratory of Gene Technology
       and Safety, Tsukuba Life Science; Center, Institute of Physical and
       Chemical Research (RIKEN),; Ibaraki, Japan.
 SO    J Virol. 1995 Dec;69(12):7606-11. Unique Identifier : AIDSLINE
       MED/96079005
 AB    Friend spleen focus-forming virus (F-SFFV) causes acute erythroleukemia
       in mice and encodes in its defective env gene an Env-like membrane
       glycoprotein (gp55). The F-SFFV env gene has three characteristic
       structures compared with that of ecotropic murine leukemia viruses
       (MuLVs): substitution by the polytropic MuLV env sequence, a 585-bp
       deletion, and a 1-bp insertion. All of these characteristic structures
       are essential for the leukemogenic potential of gp55 of
       polycythemia-inducing isolates of F-SFFV (F-SFFVp). The 1-bp insertion
       causes changes of six amino acids and truncation by 34 amino acids at
       the C terminus. In this study, we constructed 12 mutant F-SFFV genomes
       starting from the wild-type F-SFFVp and examined the effect of the
       C-terminal truncation and the six altered amino acids on the pathogenic
       activity of gp55. The results indicated that at least 18 to 24 amino
       acids must be deleted from the C terminus for the env product to be
       pathogenically active. We also found that the six altered amino acids
       contributed significantly to the pathogenic activity of gp55. Analyses
       of the cellular processing of these mutant gp55s supported a correlation
       between the pathogenic activity of gp55 and its efficiency in overall
       cellular processing.
 DE    Amino Acid Sequence  Animal  Base Sequence  DNA Insertion Elements
       *Genes, env  Glucosamine/METABOLISM  Leukemia Viruses, Murine/GENETICS
       Leukemia, Erythroblastic, Acute/PHYSIOPATHOLOGY/*VIROLOGY  Leukemia,
       Experimental/PHYSIOPATHOLOGY/*VIROLOGY  Mice  Molecular Sequence Data
       Mutagenesis, Insertional  Mutagenesis, Site-Directed
       Oligodeoxyribonucleotides  Recombinant Proteins/BIOSYNTHESIS/METABOLISM
       Sequence Deletion  Spleen Focus-Forming Viruses/*GENETICS/*PATHOGENICITY
       Support, Non-U.S. Gov't  Transfection  Viral Envelope
       Proteins/*BIOSYNTHESIS/METABOLISM  Virulence/GENETICS  3T3 Cells
       JOURNAL ARTICLE

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

