Figure 8.

Overview of Cas9 approach for transcriptional activation and repression of gene/s. (a) RNA guided transcription activation can be achieved by fusing the dCas9 with VP64. (b) Transcription activation by chimeric sgRNA, capable of recruiting activation domains (MS2-VP64). (c) Transcriptional activation by the dCas9-p300 system. (d) SAM based transcriptional activation of endogenous genes. The SAM complex consists of dCas9-VP64 complex, sgRNA with two MS2 RNA aptamers, and MS2 RNA-binding protein (MCP) fused to activators p65 and HSF1. (e) Fusion of dcas9 with KRAB repressor can be used to achieve transcriptional repression. (f) Cas9 acts as a repressor by sterically blocking the transcription machinery. (g) Cas9 acts as a repressor by blocking transcription elongation.