Poliovirus infection of HeLa cells inhibited host protein synthesis initiation by 90% at 2 hours post-infection, with the lesion primarily associated with the crude polyribosome fraction.
Poliovirus infection inhibits host cell protein synthesis at the initiation stage, likely due to a viral-induced alteration in the ribosomal wash fraction.
The inhibition of HeLa cell protein synthesis by poliovirus was studied by examining initiation in vitro on endogenous host polyribosomes. At an early stage, before major viral RNA replication and protein synthesis begins, the initiation of translation on cellular mRNA is strongly inhibited. Fractionation of extracts from infected cells shows that the lesion is associated mainly with the crude polyribosome fraction. The cellular mRNA appears unchanged and is as active as mRNA from control cells in stimulating incorporation. The native ribosomal subunits and KCl-washed polyribosomes from the infected cells are also active. Only the ribosomal wash fraction prepared from the inhibited polyribosomes had reduced activity. However, the reduction in the ribosomal wash activity measured in a reconstructed system is not as large as the inhibition seen with "native" polyribosomes. The results indicate that a viral induced inhibition is probably associated with the ribosomal wash fraction, but the reconstructed system is not equivalent to the "native" inhibited system.
Kaufmann et al. (1976) studied Poliovirus infection (in vitro). Poliovirus infection vs. Mock-infected control cells was evaluated on Initiation of protein synthesis (f[35S]Met incorporation). Poliovirus infection of HeLa cells inhibited host protein synthesis initiation by 90% at 2 hours post-infection, with the lesion primarily associated with the crude polyribosome fraction.