CRISPR-Based Technologies: Impact of RNA-Targeting Systems

Abstract

DNA-targeting CRISPR-Cas systems, such as those employing the RNA-guided Cas9 or Cas12 endonucleases, have revolutionized our ability to predictably edit genomes and control gene expression. Here, I summarize information on RNA-targeting CRISPR-Cas systems and describe recent advances in converting them into powerful and programmable RNA-binding and cleavage tools with a wide range of novel and important biotechnological and biomedical applications.

Keywords: CRISPR; Cas10; Cas13; Cas9; RNA editing; RNA targeting; Type III CRISPR-Cas systems; Type VI CRISPR-Cas systems; gene editing.

Figure 1.

Type III CRISPR systems employ multiple-subunit crRNP effector complexes and function through both RNA and DNA targeting mechanisms. Target RNA binding by the crRNP effector complexes activates three distinct nucleases (two RNases and one DNase) that collectively destroy transcriptionally active target DNA and RNA substrates.

Figure 2.

Type VI CRISPR systems use a single Cas13 effector RNAse and function through targeting the cleavage of RNAs in cis and trans. A) wildtype Cas13-crRNA systems as well as B) RNase-defective (dCas13) systems including C) those with fused effector domains of other proteins support a wide range of established or potential RNA targeting applications.