FIGURE 5.

Identification of the key residues in the s2, s4, s6, s7, s9, s10, and s11 regions for the ALV-A binding receptor and invading cells. (A,C,E) Schematic representation of amino acid substitutions in s2 and s6, s4 and s10, or s7, s9, and s11. (B,D,F) DF-1 cells were incubated with mutant gp85 proteins with amino acid substitutions in s2 and s6 or s4 and s10 or s7, s9, and s12 and subsequently infected with RCASBP (A)-EGFP. The percentage of GFP-positive cells was measured by FACS for blocking analysis. (G) DF-1 cells transfected with recombinant RCASBP (A/E)-EGFP vectors with amino acid substitutions in s3, s5, s8, and s12 were detected for the percentage of GFP-positive cells by FACS 5 days posttransfection. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.