RNase L - Synthesis and Activation

Synthesis and Activation

RNase L is present in very minute quantities during the normal cell cycle. When interferon binds to cell receptors, it activates transcription of around 300 genes to bring about the antiviral state. Among the enzymes produced is RNase L, which is initially in an inactive form.

Activation occurs by the following:

1. dsRNA in the cytoplasm stimulates 2'-5' oligo(A) synthetase to produce strands of 2'-5' adenylic acid (versus the normal 3'-5'; ATP-dependent);
2. these strands induce activation of RNase L which then forms a dimer and proceeds to degrade all RNA within the cell.