Role of lysine in the replication of reovirus

Summary

Omission of lysine from the extracellular medium of HeLa cells infected with reovirus type 2 results in the production of virus structures which could be separated by isopycnic sedimentation in CsCl into a top band of empty particles (L-T) and a bottom band (L-B) containing a mixture of defective and complete virus structures. The L-T and L-B particles were found to be similar to the complete virus in the following properties: adsorption characteristics to HeLa cells, RNA base composition, and qualitative distribution of the double-stranded viral RNA segments and structural viral proteins.

Polyacrylamide gel electrophoresis analyses of the capsid proteins of L-T and L-B particles indicated a quantitative alteration in the distribution of their protein components. In addition, L-T particles contained markedly reduced amounts of the single-stranded adenine-rich RNA component. The synthesis of viral double-stranded RNA and cytoplasmic proteins were both reduced in lysine-deficient cell cultures. In contrast, the synthesis of single-stranded RNA remained unaltered. Addition of increasing concentrations of lysine to lysine-deficient cultures resulted in increasing yields of infectious virus.