Association of Foot-and-Mouth Disease Virus Replicase with RNA Template and Cytoplasmic Membranes

The association of the replicase of foot-and-mouth disease virus (FMDV) with cellular membranes was suggested following attempts to produce a soluble enzyme by the use of detergents (Arlinghaus & Polatnick, 1967, 1969; Delagneau, 1971), as described for the purification of poliovirus replicase (Ehrenfeld, Maizel & Summers, 1970). Subsequently, the association with cellular membranes of the replicase and the single-stranded and replicative forms of RNA was reported for poliovirus (Caliguiri & Tamm, 1969, 1970a, b), for Semliki Forest virus (Friedman et al., 1972) and for tobacco mosaic virus (Ralph, Bullivant & Wojcik, 1971). In each case, the replicase-membrane complex contained endogenous RNA template (Arlinghaus & Polatnick, 1969; Caliguiri & Tamm, 1969; Ehrenfeld et al., 1970; Friedman et al., 1972). We show in this communication that FMDV replicase is associated with ribosome-containing membranes and requires glycerol to stabilize its activity during sedimentation in the presence of detergents.