An unnatural enzyme with endonuclease activity towards small non-coding RNAs.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37355703.
- Also identified by DOI 10.1038/s41467-023-39105-0 and PMC identifier 10290691.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Endonucleases are enzymes that cleave internal phosphodiester bonds within double-stranded DNA or RNA and are essential for biological functions. Herein, we use genetic code expansion to create an unnatural endonuclease that cleaves non-coding RNAs including short interfering RNA (siRNA) and microRNAs (miRNAs), a function that does not exist in nature. We introduce a metal-chelating unnatural amino acid, (2,2'-bipyridin-5-yl)alanine (BpyAla) to impart endonuclease activity to the viral suppressor of RNA silencing protein p19. Upon binding of copper, the mutant p19-T111BpyAla displays catalytic site-specific cleavage of siRNA and human miRNAs. Catalysis is confirmed using fluorescence polarization and fluorescence turn-on. Global miRNA profiling reveals that the engineered enzyme cleaves miRNAs in a human cell line. The therapeutic potential is demonstrated by targeting miR-122, a critical host factor for the hepatitis C virus (HCV). Unnatural endonuclease function is shown to deplete miR-122 levels with similar effects to an antagomir that reduces HCV levels therapeutically.
Medical subject headings
- MicroRNAs