The 2-5A (pppA2'p5'A2'p5'A) and protein kinase systems in interferon-treated and control cells.

With respect to interferon action in general: multisite models and analogies with hormone action are in vogue. More particularly, concerning the 2-5A system, the structure of 2-5A has been confirmed. We know that in the cell-free system and intact cell it is unstable and in the absence of a regenerating system transiently activates a nuclease. This nuclease shows some specificity; preferentially cleaving RNA on the 3'-side of UN doublets (UA and UU are preferred). When introduced into the intact cell 2-5A can inhibit protein and DNA synthesis and virus growth. In addition, both 2-5A and core occur naturally in amounts sufficient for them to play a part in the antiviral and antigrowth activities of interferon. Finally, it is possible that the 2-5A system may have a significance beyond its role in interferon action in the control of cell growth or development.