June 2, 2016
(The Scientist) – Much attention paid to the bacterial CRISPR/Cas9 system has focused on its uses as a gene-editing tool. But there are other CRISPR/Cas sytems. Researchers from MIT and the National Center for Biotechnology Information (NCBI) last year identified additional CRISPR proteins. One of these proteins, C2c2, seemed to be a putative RNA-cleaving—rather than a DNA-targeting—enzyme, the researchers reported at the time. Now, the same group has established that C2c2 indeed cleaves single-stranded RNA (ssRNA), providing the first example of a CRISPR/Cas system that exclusively targets RNA. The team’s latest results, published today (June 2) in Science, confirm the diversity of CRISPR systems and point to the possibility of precise in vivo RNA editing.