The 2-5A (pppA^2′ p^5′ A^2′ p^5′ A) system in interferon-treated and control cells

An investigation into the inhibition of protein synthesis by double-stranded RNA in cell-free systems prepared from interferon-treated cells has resulted in the identification of at least two enzymes (the 2-5A synthetase and protein kinase) which are induced in response to interferon. In addition, the discovery that the 2-5A synthetase is present in a wide variety of cells and tissues in the absence of interferon treatment and is also capable of using important metabolites as substrates has suggested a possible wider significance for the 2-5A system in the control of cell growth and development.