RNase2

RNASE2, or eosinophil-derived neurotoxin (EDN), is a human gene encoding a secreted ribonuclease of the RNase A superfamily. The protein is expressed predominantly in eosinophils and stored in their granules; upon activation it is released to extracellular spaces and body fluids. The precursor includes a signal peptide and is processed to a mature secreted enzyme that is glycosylated.

Biochemical activity: EDN retains ribonuclease activity, catalyzing cleavage of single-stranded RNA. This enzymatic activity contributes to its role in innate immunity and antiviral defense. In addition to its enzymatic function, EDN can exhibit neurotoxic effects at higher concentrations, which underlies its designation as a neurotoxin in earlier literature.

Biological and clinical relevance: EDN is a component of eosinophil-driven inflammation and has been studied as a biomarker of eosinophil activation in allergic diseases such as asthma. Elevated EDN levels in serum, sputum, or other fluids can reflect eosinophilic activity. Evolutionarily, RNASE2 is part of a conserved RNase A superfamily; related proteins include RNASE3 (eosinophil cationic protein).

Genetics: The RNASE2 gene forms part of the eosinophil ribonuclease gene cluster in humans; multiple family members encode related secreted RNases. The precise roles of EDN in health and disease are active areas of research, including its antiviral properties and interactions with immune cells.