Effects of K+ concentration on inhibition of protein synthesis by trimer and tetramer triphosphates of 2',5'-oligoadenylates in rabbit reticulocyte lysates

The inhibition of protein synthesis by trimer or tetramer triphosphates of 2',5'-oligoadenylates (2-5A) in rabbit reticulocyte lysates is dependent on the concentration of K+ in the assay mixture. Based on studies using mRNA-dependent rabbit reticulocyte lysates and the degradation of [3H] polyadenylated mRNA, the greater inhibitory effects of trimer or tetramer triphosphates at the higher K+ is shown to be due to a more active 2-5A-dependent endoribonuclease (RNase L).