[Regulation of the 2',5'-oligoadenylate level in mouse L cells]

A study of pH dependence for ppp5'A2'p5'A2'p5'A hydrolysis in interferon treated and untreated mouse L-cells extracts led to the detection of two types of the 2'-phosphodiesterase activities: interferon dependent and interferon resistant. Several pH-optima were observed for hydrolysis of ppp5'A2'p5'A2'p5'A in cell extracts after their treatment with non-ionic detergent NP-40 or their differential centrifugation. The 2'-phosphodiesterase activity was found in the membrane fraction as well as in the cytoplasmic one. The presence of several pH-optima for 2'-phosphodiesterase activity in L-cells and changes of the level of this activity depending on the growth stage of cells and time of their interferon treatment indicate the complicated character of the regulation of 2'-5'-oligoadenylate's concentration and localization. The results obtained suggest that in mouse L-cells several 2'-phosphodiesterases or one enzyme in different forms may be present.