SRP329721 PRJNA749464 GSE180773 Engineered miniature CRISPR-Cas system for mammalian genome regulation and editing Compact and versatile CRISPR-Cas systems will enable genome engineering applications through high-efficiency delivery in a wide variety of contexts. Here we create an efficient miniature Cas system (CasMINI) engineered from the type V-F Cas12f (Cas14) system by guide RNA and protein engineering, which is less than half the size of currently used CRISPR systems (Cas9 or Cas12a). We demonstrate that CasMINI can drive high levels of gene activation (up to thousands-fold increases), while the natural Cas12f system fails to function in mammalian cells. We show that the CasMINI system has comparable activities to Cas12a for gene activation, is highly specific, and allows for robust base editing and gene editing. We expect that CasMINI can be broadly useful for cell engineering and gene therapy applications ex vivo and in vivo. Overall design: mRNA profiles of dCasMINI-VPR and dCas12a-VPR activations. Samples were generated by deep sequencing, in replicate, using illumina NovaSeq 6000 platform. GSE180773 pubmed 34480847