Fig. 2.

Identification of residues in FcaA3Z3 for FIV Vif induced degradation. a Expression plasmids for FcaA3Z3, HsaA3H and big cat A3Z3s were co-transfected with FIV Vif into 293T cells. Cell lysates were analyzed by immunoblot. A3s contain a C-terminal HA-tag, Vifs contain a C-terminal V5-tag. FcaA3s represent domestic cat (Felis catus) APOBEC3s. Pti, Ple, Lly and Pco represent Panthera tigris corbetti; Panthera leo bleyenberghi; Lynx lynx; Puma concolor. b Scheme of FcaA3Z3/HsaA3H.hapII chimeras (Z3C1, -C2, –C6, -C7). Highlighted sequence diversity between HsaA3H and FcaA3Z3 in an N-terminal region. c 293T cells were co-transfected with expression plasmids for FcaA3Z3, Z3C1, Z3C2, Z3C6, Z3C7 or HsaA3H hapII and FIV Vif, HIV-1 (NL4-3 or LAI) or SIVmac Vif. The expression of chimeras and Vif proteins were detected by using anti-HA and anti-V5 antibodies, respectively. Tubulin served as loading control. d Amino acid logo for the N-terminus in 15 A3Z3 sequences from ten Carnivores species (upper panel) and for eight A3Z3 sequences from eight Primates species (lower panel). Residues identified to evolve under purifying selection are labelled with “pur”. No residue was identified to evolve under diversifying selection in this A3Z3 stretch