FIG. 6.

Defined feline APOBEC3 proteins inhibit HIV-1 infectivity to different degrees. (A) Analysis of feline APOBEC3C (feA3C; lane 1), APOBEC3H (feA3H; lane 3), and APOBEC3CH (feA3CH; lane 5) expression by RT-PCR of total RNA from feline CrFK cells. In lanes 2, 4, and 6, PCRs using the primers specific for feA3C (lane 2), feA3H (lane 4), and feA3CH (lane 6) were performed without template cDNA added. (B) HIV-Luc(VSV-G) was produced in 293T cells in the presence or absence of the indicated feline APOBEC3. Infectivity of the viruses was determined by quantification of luciferase activity in HOS cells infected with equal amounts of viruses 3 dpi. (C) A fragment in LTR-gag was amplified from reverse transcripts of HIV-Luc generated in the presence of the indicated feline APOBEC3 10 h postinfection. A total of 5 to 10 independent nucleotide sequences were determined. The mutations in the clones of each group are shown. Each mutation is indicated and coded with respect to nucleotide mutation. (D) Comparison of the dinucleotide sequence context of G (underlined)→A mutations in the positive-strand DNA of HIV-Luc derived from CrFK cells and from feAPOBEC3-expressing 293T cells.