CRISPR/Cas9 screen to identify genes involved in uptake of cell-penetrating peptides (Raji). Homo sapiens

Cell-permeable peptides (CPPs) allow intracellular delivery of cargo molecules that are hooked to them. CPPs provide an efficient methodology to transfer bioactive molecules in cells, in particular in conditions when transcription or translation of cargo-encoding sequences is not desirable or achievable. The mechanisms allowing CPPs to enter cells are ill-defined and controversial. No genes have been described that regulate the intracellular delivery of CPPs. Using a CRISPR/Cas9-based screening, we discovered that the KCNQ5, KCNN4, and KCNK5 potassium channels are required for direct cellular translocation of TAT-RasGAP317-326 anti-cancer compound in various cell lines by setting the appropriate transmembrane potential of the cells. These potassium channels also affected the cellular uptake of other TAT-bound cargos.