Protein Synthesis in Cells Infected with Bovine Rotavirus

Summary Bovine rotavirus was found to multiply efficiently in LLC-MK2 cells, a continuous line of rhesus monkey kidney, with a growth cycle which was essentially completed within 9 h after infection. The presence of low concentrations of trypsin (10 µg/ml) in the virus inoculum was essential for infectivity. Polyacrylamide gel electrophoresis of infected cell extracts demonstrated the synthesis of at least eight virus-specific polypeptides 6 h post-infection with mol. wt. ranging from 102 × 103 to 29 × 103. Six polypeptides (about p102K, p91K, p84K, p45K, p37K and p34K) were identified as structural components of the virion. Two other polypeptides (p54K and p29K) were identified as non-structural components. The synthesis of non-structural polypeptides appeared to precede that of the structural proteins. Pulse-chase experiments showed only one minor post-translation modification of the virus-specified proteins, namely an increase in the mobility of the 29K polypeptide.