Learning RNA Targeting Rules of the CRISPR Effector C2c2

Jonathan Gootenberg, Harvard University

The CRISPR-Cas adaptive immune system defends microbes against foreign genetic elements via DNA or RNA-DNA interference. We recently characterized the Class 2 type VI-A CRISPR-Cas effector C2c2 and demonstrated its RNA-guided RNase function. C2c2 orthologs are capable of providing protection against RNA phage, degrading ssRNA in vitro, knocking down specific mRNA in bacteria and reducing expression of targeting genes in mammalian cells. To determine specific rules for designing effective guide RNA, we screened all possible RNAs across a panel of 13 genes and used sequence and structural features of the RNA to construct a predictive efficiency model. These results broaden our understanding of CRISPR-Cas systems and will enable the development of C2c2-based RNA-targeting tools.

Abstract Author(s): J.S. Gootenberg, O.O. Abudayyeh, J. Joung, A. Regev, E.S. Lander, F. Zhang