The P-rich motif is important but not essential for chikungunya virus replication in mammalian and mosquito cells.

(A) Vero and Aag2 cells were transfected with in vitro transcribed RNA of CHIKrep or CHIKrepΔPVA and the relative luciferase expression was quantified at 24 hpt. Bars indicate the mean relative light units (RLU) ±standard error of the mean from three independent experiments. (B/C) Vero (B) and Aag2 (C) cells were infected in duplicate with CHIKIC, CHIKICP398A or CHIKICPPR401AAA at a multiplicity of infection (MOI) of 0.01. TCID50/ml was determined by EPDA on Vero cells at the indicated time-points. (D) Aag2 cells were infected in duplicate with CHIKIC, CHIKICP398A or CHIKICPPR401AAA at an MOI of 5 and the TCID50/ml was determined by EPDA on Vero cells at the indicated time-points. Asterisks indicate significant differences compared to the wild type virus by one-way ANOVA with Tukey’s post-hoc test on Log10 transformed data at each time-point (α = 0.05). The dotted line in panels B-D indicates the EPDA detection limit.