Cas13a/C2c2 - A Dual Function Programmable RNA Endoribonuclease

Patent Status

Brief Description

Bacterial adaptive immune systems employ CRISPRs and CRISPR-associated (Cas) proteins for RNA-guided nucleic acid cleavage. Although generally targeted to DNA substrates, the Type VI CRISPR system directs interference complexes against single-stranded RNA substrates and in Type VI CRISPR systems, the single-subunit Cas13a/C2c2 protein functions as an RNA-guided RNA endonuclease.

UC Berkeley researchers have discovered that the CRISPR-Cas13a/C2c2 has two distinct RNase activities that enable both single stranded target RNA detection and multiplexed guide-RNA processing.  These dual RNase functions were found to be chemically and mechanistically different from each other and from the CRISPR RNA processing behavior of the evolutionarily unrelated CRISPR enzyme Cpf1.  Methods for detecting the single stranded target RNA were also discovered using a Cas13a/C2c2 guide RNA and a Cas13a/C2c2 protein in a sample have a plurality of RNAs as well as methods of cleaving a precursor Cas13a/C2c2 guide RNA into two or more Cas13a/C2c2 guide RNAs.

Suggested uses

• Multiplexed guide-RNA processing
• Diagnostic for sensitive target RNA detection

Advantages

• Detects target RNA directly without considerable engineering or stringent design constraints for each new RNA target
• Cleavage potent and detectable at extremely low levels of activated protein
• Highly specific method of detection
• Conventional detection methods can be used (e.g., using a labeled detector RNA)

Publication

Two distinct RNase activities of CRISPR-C2c2 enable guide-RNA processing and RNA detection