Interferon Stimulated Exonuclease Gene 20kDa Like Protein 2 (ISG20L2)

Truncation experiments demonstrated that the C terminus of ISG20L2 was sufficient to produce nucleolar localization. GST/ISG20L2 fusion experiments confirmed that the purified protein possessed 3-prime to 5-prime exoribonuclease activity. Coimmunoprecipitation studies showed that ISG20L2 associated with several ribosomal proteins through its N terminus. When overexpressed, ISG20L2 caused a specific decrease in 12S precursor rRNA and, conversely, an increase when it was silenced.

The deduced 353-amino acid protein, designated ISG20L2, has a predicted exonuclease domain between amino acids 178 and 344. In S. cerevisiae, Rex4 is involved in ribosome biogenesis.