       Document 0568
 DOCN  M9640568
 TI    Influence of ORF2 on host cell tropism of feline immunodeficiency virus.
 DT    9604
 AU    Waters AK; De Parseval AP; Lerner DL; Neil JC; Thompson FJ; Elder JH;
       Department of Molecular Biology, Scripps Research Institute, La; Jolla,
       California 92037, USA.
 SO    Virology. 1996 Jan 1;215(1):10-6. Unique Identifier : AIDSLINE
       MED/96146738
 AB    Feline immunodeficiency virus (FIV) is a lentivirus associated with an
       immunodeficiency syndrome of the domestic cat. A short open reading
       frame (ORF2), of unknown function, is present in all FIV isolates. We
       have investigated the role of ORF2 in determining the cell tropism of
       two infectious molecular clones of FIV. FIV-PPR is able to productively
       infect feline peripheral blood leukocytes (PBLs) and a T lymphocyte cell
       line (MCH5-4), but not a feline astrocyte cell line (G355-5) or Crandell
       feline kidney cells (CrFK). In contrast, FIV-34TF10 is able to
       productively infect G355-5 and CrFK cells, but not PBLs or MCH5-4 cells.
       The major difference in these FIV clones is that ORF2 in FIV-PPR is
       capable of encoding a 79-amino-acid peptide, whereas there is a stop
       codon in ORF2 after 43 amino acids in FIV-34TF10. We performed
       site-directed mutagenesis to change the stop codon (TGA) in FIV-34TF10
       to a tryptophan (TGG), the amino acid present at this location in
       FIV-PPR. FIV-34TF10 with ORF2 repaired (FIV-ORF2rep) productively
       infected PBLs, MCH5-4 cells, and primary macrophages, as well as CrFK
       and G355-5 cells, indicating that a protein encoded by ORF2 plays a role
       in determining the host cell tropism of FIV. ORF2 contains hydrophobic,
       acidic, and leucine-rich domains similar to those shown to be important
       for transactivating proteins of other lentiviruses. Coexpression of a
       plasmid expressing the ORF2 gene product with another construct
       expressing the chloramphenicol acetyl transferase (CAT) gene driven by
       the FIV LTR, resulted in transactivation of CAT expression in both
       feline and human cells.
 DE    Amino Acid Sequence  Animal  Base Sequence  Cats  Cells, Cultured  DNA,
       Viral/GENETICS  Human  Immunodeficiency Virus, Feline/CHEMISTRY/*GROWTH
       & DEVELOPMENT/  GENETICS/ISOLATION & PURIF  Molecular Sequence Data
       Mutagenesis, Site-Directed  Open Reading Frames  Structure-Activity
       Relationship  Support, U.S. Gov't, P.H.S.  Trans-Activation (Genetics)
       Transfection  Viral Proteins/CHEMISTRY/*PHYSIOLOGY  JOURNAL ARTICLE

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

