The fusion of three transcriptional activation domains to a nuclease-deficient Cas9 achieves robust induction of gene expression and can induce differentiation of hiPSCs. The RNA-guided nuclease Cas9 can be reengineered as a programmable transcription factor. However, modest levels of gene activation have limited potential applications. We describe an improved transcriptional regulator obtained through the rational design of a tripartite activator, VP64-p65-Rta (VPR), fused to nuclease-null Cas9. We demonstrate its utility in activating endogenous coding and noncoding genes, targeting several genes simultaneously and stimulating neuronal differentiation of human induced pluripotent stem cells (iPSCs).

Highly efficient Cas9-mediated transcriptional programming