FIG 4.

Accumulation of viral mRNAs and proteins in infected HeLa/CD26 cells. HeLa/CD26 cells were mock infected (Mock) or infected with MERS-CoV-WT (WT) or MERS-CoV-Δp4 (Δp4) at an MOI of 3. At the indicated times p.i., total intracellular RNAs and proteins were prepared. (A) Northern blot analysis of viral mRNAs using a riboprobe that binds to all viral mRNAs. The numbers 1 to 8 represent viral mRNA species. The 28S and 18S rRNAs were detected by ethidium bromide staining (rRNA). (B and C) The amounts of mRNA 1 (B) and subgenomic mRNA 8 (C) were quantified by qRT-PCR. The expression levels of mRNAs were normalized to the levels of 18S rRNA. Each bar represents the mean (±standard deviation) for three independent samples. ns, not significant (P > 0.05). (D) Western blot analysis of intracellular accumulation of the MERS-CoV S, M, and N proteins and tubulin.