The bet gene of feline foamy virus is required for virus replication.
Foamy viruses (FV) are complex retroviruses with additional bel genes located between env and the 3' long-terminal repeat. The functions of the bel 2 and bet genes are unknown and both are dispensable for replication of the prototypic human foamy virus in cell cultures. We examined the function(s) of bel 2 and bet of the distantly related feline foamy virus (FFV) in the proviral context. Mutagenesis was used to alter the Bel 2 and Bet or to abrogate their expression. The Bel 2/Bet mutants showed a 1000-fold reduced viral titer in feline kidney cells; in human 293T cells, viral titer was only about 10-fold reduced compared to wild-type FFV. In both cell types, the Bel 2/Bet mutations resulted in a reduced release of FFV particles. The results indicate that FFV Bet is required for efficient virus replication. The functions of the Bel 2 and Bet proteins are discussed.
Alke
A
A
Abteilung Retrovirale Genexpression, Forschungsschwerpunkt Angewandte Tumorvirologie, Deutsches Krebforschungszentrum, Heidelberg, Germany.
Schwantes
A
A
Kido
K
K
Flötenmeyer
M
M
Flügel
R M
RM
Löchelt
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002371:Cat Diseases / Q000821:virology; D002415:Cats; D002478:Cells, Cultured; D017353:Gene Deletion; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D011533:Proviruses / Q000235:genetics* / Q000648:ultrastructure; D016092:Spumavirus / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D020079:Terminal Repeat Sequences; D014764:Viral Proteins / Q000235:genetics*; D014771:Virion / Q000502:physiology
C435104:FFVBel2 protein, feline foamy virus; D014764:Viral Proteins