Areas of Interest
CRISPR-Cas technologies have accelerated biology research, leading to advances in genetics, biomedicine, and bio-production. Traditional approaches adapted RNA-guided, single-protein Cas9 nucleases to create programmable double stranded DNA breaks (DSBs), enabling targeted gene disruption or homology repair (HR)-mediated knock-ins. However, these Cas9 nuclease methods suffer from key drawbacks including low edit efficiencies, genomic translocations, and unwanted insertions and deletions (indel) byproducts. Additionally, many genomic targets are not accessible by conventional Cas9 and Cas12 systems due to restrictive protospacer adjacent motifs (PAMs). Lastly, some Cas nucleases can be toxic to common research models.To enable more flexible and tunable editing outcomes, our lab investigates the mechanisms and applications of Type I CRISPR systems. As the most abundant and diverse subclass of CRISPR, the main uniting characteristic of Type I sytems is that they complete targeted-DNA binding through a multi-protein Cas moiety known as Cascade. The Cascade complex recognizes DNA targets that are complementary to their CRISPR RNA (crRNA). Unlike Cas9 or Cas12, Cascade does not have nuclease activity, and instead recruits an additional Cas3 protein which processively degrades DNA. The separation of surveillance and degradation, broad PAM diversity, and unique multisubunit composition of Type I CRISPR systems make them an exciting prospect for novel genome editing tools. My work involves genetics and in vitro biochemistry to elucidate mechanistics of Type I CRISPR DNA recognition and degradation, and their transfer to application in eukaryotes.