FIG 4.
P4 Arg-to-His substitution rescues CHIKV replication in the absence of the nsP3-G3BP interaction. (A) BHK-21 cells were electroporated with infectious cDNA of WT CHIKV, the G3BP-binding mutant CHIKV F3ANC, and CHIKV F3ANC-RH, and infectivity was assessed by ICA. (B) BHK-21 cells were electroporated with infectious cDNA plasmid and viral titers quantified by plaque assay at the indicated time points. †, time point at which electroporated cells had died. (C) CHIKV F3ANC virus, rescued 72 h postelectroporation from panel B, was passaged 5 times and plaque purified, and 2 clones were subjected to sequence analysis. Both clones as well as pool of passage 5 viruses shared a mutation resulting in a restoration of an FGDF motif via a 29-amino-acid deletion, flanked by an N-terminal FG and a C-terminal DF motif (underlined).