Ribonuclease L

Ribonuclease L or RNase L is a latent enzyme that cleaves the components of RNA. Its increased production is activated by interferon which, in turn, causes the destruction of all RNA within the cell, both cellular and viral. It is a key component of the intracellular immune response to viral pathogens.

RNase L is present in small quantities during the normal cell cycle. When interferon binds to receptors on the cell membrane, it triggers the production of more RNase L along with 2'-5' Oligodenylate Synthetase (OAS). OAS converts ATP to pyrophosphate and 2'-5'linked oligoadenylates. The 2-5 A molecules bind to RNase L and activates it. The activated RNaseL destroys all cellular and viral RNA, which triggers autophagy and programmed cell death.

Several abnormalities of the 2-5A/RNaseL pathways have been documented in chronic fatigue syndrome patients and have been suggested a possible diagnostic biomarker. Studies of peripheral blood mononuclear cells have found that the RNase L and 2-5 A pathways are dysregulated, with abnormally high levels of the active form of 2-5 A. RNase L proteins of the molecular weights 80, 42 and 37 kDa have also been found.

RNaseL activity and concentrations of bioactive 2-5 A are correlated with physical function.

Notable studies

 * 2001, G-Actin Cleavage Parallels 2-5A-Dependent RNase L Cleavage in Peripheral Blood Mononuclear Cells—Relevance to a Possible Serum-Based Screening Test for Dysregulations in the 2-5A Pathway - (Abstract)
 * 2001, Interactions Between Rnase L Ankyrin-Like Domain and ABC Transporters as a Possible Origin for Pain, Ion Transport, CNS and Immune Disorders of Chronic Fatigue Immune Dysfunction Syndrome - (Abstract)