cGPS^®: the cellular Genome Positioning System  revolution

cGPS^® products send your transgene to the desired destination in no time

Targeted integration corresponds to the stable genomic integration of a DNA sequence, most of the time a transgene expression cassette, at a unique genomic position. The unique genomic position has been selected to guarantee an adequate transcriptional activity.

Any transgene expression cassette or shRNA, can be integrated at the meganuclease recognition site. Over expression is achieved following transgene integration, while RNA Silencing studies can be conducted the same way with the same benefits of targeted integration.

cGPS^® principle

Targeted integration involves a “cut and paste” process, performed by a Meganuclease and Homologous Recombination, respectively. A meganuclease expression vector is co-transfected together with a DNA Integration Matrix. Following transfection, the meganuclease enters the nucleus and recognizes its recognition site, binds to it and induces a DNA double-strand break (“cut”). The cell senses the DNA damage and uses homologous recombination to fix it. The co-transfected Integration Matrix, containing  the 5’ and 3’ homology regions flanking the meganuclease recognition site, is used as template by the cell for homologous recombination. The Integration Matrix also contains a Multiple Cloning Site to easily clone a transgene expression cassette.  Following homologous recombination, the transgene expression cassette gets stably integrated (“paste”) at the exact meganuclease recognition site.

Meganuclease-driven targeted integration is based on the presence of a meganuclease recognition site within the targeted cell genome. Although a natural meganuclease recognition site is not present in mammalian cells (since meganucleases are naturally occurring enzymes from single-celled organisms), meganuclease-driven targeted integration can be achieved two ways in higher eukaryotic cells:

• the recognition site of a natural meganuclease is integrated in the targeted host cell as a single copy. This is the principle of our cGPS^® line of targeted integration kits;
• a natural meganuclease is engineered so as to change its recognition site and to target a native genomic locus (an endogenous gene f.i.). This is the principle of our cGPS^® Custom line of targeted integration kits

 cGPS^® strategy