Organisms must regulate gene expression and also distinguish their RNA molecules (self) from the RNAs of invading viruses (non-self). Biochemical and structural studies from Bass, Shen, Iwasa, and colleagues revealed how Dicer-2, an RNA processing, and antiviral defense enzyme, distinguishes and differentially processes double-stranded RNA (dsRNA) substrates by sensing the unique chemistry at their termini. The study also revealed that human Dicer evolved with distinct activities from invertebrate Dicers, and this discovery is paving the way for altering the antiviral defense for therapeutic benefits.
Dicer uses distinct modules for recognizing dsRNA termini. Sinha NK, Iwasa J, Shen PS, Bass BL. Science. 2018 Jan;359(6373):329.
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