Exosome Component 2 (EXOSC2)

Mammalian mRNAs contain AU-rich elements (AREs) within their three prime untranslated regions. In yeast, 3-prime-to-5-prime mRNA degradation is mediated by the exosome, a multisubunit particle. EXOSC2 (which is homologous to the yeast Rrp4 protein) is a component of the human exosome.

The protein encoded by this gene is required for a 3-prime to 5-prime exonuclease activity that generates the 3-prime end of the 5.8S rRNA. The yeast protein, as well as its human homolog, is only 1 enzymatic subunit of a multienzyme ribonuclease complex that Mitchell et al. (1997) referred to as the 'exosome.' The human protein is 43% identical to the yeast protein. Expression of the human RRP4 gene in yeast complemented the mutation in the rrp4.1 strain.