Inhibition of protein synthesis in liver and kidney of mice by bolesatine: mechanistic approaches to the mode of action at the molecular level.

Protein synthesis was assayed in liver and kidney of mice treated with bolesatine, a toxic glycoprotein from the mushroom Boletus satanas (Lenz) which was previously shown to be an inhibitor of protein synthesis by cell-free systems in vitro and by cultured cell-lines. Protein synthesis in vivo (Swiss mice) is inhibited in a dose-dependent manner in liver and kidney. The mechanism of action does not appear to be due to RNA-N-glycosidase activity of bolesatine or a RNAase activity of this toxin on the ribosomal RNAs. Ribosomes do not appear to be damaged by pretreatment with bolesatine as judged by a poly(U) translation system. Thus bolesatine cannot be included in the group of protein synthesis inhibitors of plant origin known as ribosome-inactivating proteins (RIPs).