Host-dependent restriction of mengovirus replication. II. Effect of host restriction on late viral RNA synthesis and viral maturation

Abstract

Restricted mengovirus replication in Madin-Darby bovine kidney (MDBK) cells is characterized by a 400-fold reduction in infectious virus yield and a 40-fold increase in the production of noninfectious virus. Using conditions which insure that all MDBK cells are infected, virus-specific RNA and protein synthesis were measured in the restrictive host and in a permissive host for mengovirus, HeLa cells. Labeling kinetics and sucrose gradient analysis of mengovirus-specific RNA from MDBK cells show a reduction of 10-fold in virion RNA, 5-fold in double-stranded RNA, and 12.5-fold in single-stranded RNA. The viral RNA biosynthetic processes which occur late in the replicative cycle and result in the production of 90% of the single-stranded viral RNA that is packaged into capsid proteins in the permissive host are absent in restrictive MDBK cells. Viral protein synthesis as measured by labeled viral-specific polysome is decreased, and there is an accumulation of 80S subviral particles in the restricted host. It is suggested that restriction may act at a number of stages of viral replication and maturation.

VPg unlinkase/TDP2 in cardiovirus infected cells: Re-localization and proteolytic cleavage

“…TDP2 cleavage was observed at 6 and 8 hr post-EMCV infection in HeLa cells (refer to Fig. 5), which is the peak kinetic window for EMCV RNA synthesis in this cell line (Martin and Palmenberg, 1996; Prather and Taylor, 1975). These results have parallels with those seen for PCBP2, a host protein necessary for enterovirus translation and RNA synthesis (Chase et al, 2014; Gamarnik and Andino, 1997; Parsley et al, 1997; Walter et al, 1999; Walter et al, 2002).…”