FIG 5.

Both the transmembrane-spanning peptide and acidic cluster dileucine motif of UL138 participate in MRP1 downregulation during HCMV infection. (A) Lysates from NHDFs infected with the indicated viruses at an MOI of 3 for 48 h were analyzed by Western blotting with the indicated antibodies. Images representative of results from three independent biological replicates are shown. (B) MRP1 levels normalized to GAPDH and compared to a mock-infected control were determined by densitometry using data from the experiments whose results are presented in panel A. Data represent means ± standard deviations of results from three independent biological replicates. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, not significant (P > 0.05) (Student's t test). (C) NHDFs were infected with TB40/E-based viruses encoding HA-tagged WT UL138 (TB138-HA) or the indicated Golgi sorting motif mutants (TB138 mLL-HA; TB138 Δ4-HA) or a UL138 null virus (TBΔ138-HA) at an MOI of 0.1. Infectious progeny were isolated on the indicated day postinfection, and virus titers were determined by plaque assay. Data represent means ± SEM of results from three independent biological replicates. (D) Lysates from NHDFs infected with the indicated viruses at an MOI of 3 for 48 h were analyzed by Western blotting with the indicated antibodies. Images representative of results from three independent biological replicates are shown. (E) MRP1 levels normalized to GAPDH and compared to a mock-infected control were determined by densitometry using data from the experiments whose results are presented in panel D. Data represent means ± SEM of results from three independent biological replicates. *, P < 0.05; **, P < 0.01; ns, not significant (P > 0.05) (Student's t test).