SunTag-dCas9 Amplified Activation Nuclease

Architecture

Catalytically dead Cas9 fused to repeating GCN4 peptide epitopes. Co-expressed single-chain antibody fragment (scFv) fused to VP64 binds GCN4 repeats, recruiting multiple activation domains per dCas9.

Characteristics

Amplified CRISPRa system recruiting up to 10× VP64 domains per dCas9. Achieves very strong activation (100-10,000× at some loci). Most potent activation system but requires two-component expression. Particularly useful for activating recalcitrant genes.

Literature References

1. Mali et al. (2013). CAS9 transcriptional activators for target specificity screening and paired nickases for cooperative genome engineering. Nat Biotechnol - Mali 2013 Cas9 Nickase
2. Tanenbaum et al. (2014). A protein-tagging system for signal amplification in gene expression and fluorescence imaging. Cell - Tanenbaum 2014 SunTag