Optogenetic regulation of transcription (ORT) could potentially be used to regulate the production of a biological drug in situ, by repeatedly applying light to the tissue, and inducing expression of therapeutic transgenes when needed. Red and near infrared wavelengths, which are capable of penetration into tissues, have potential for therapeutic applications.
Combination of Cry2/CIB1 system with bacterial DNA-binding protein LexA was used to demonstrate light-inducible transcription activation in Drosophila melanogaster—both in cell culture and in vivo [37]. Recently, CRY2/CIB1 activation by blue light was joined with CRISPR technology to create a light-activated CRISPR/Cas9 effector (LACE) system. LACE was successfully employed to simultaneously and reversibly activate human IL1RN, HBG1/2, or ASCL1 promoters in HEK293T cells.
An engineered bacterial DNA-binding LOV protein EL222 resulted in a luciferase reporter systems with highly linear response to blue light, rapid activation (<&#8201;10 s) and deactivation (<&#8201;50 s) kinetics and a large (>&#8201;100-fold) dynamic range of target protein expression in mammalian cells and zebrafish embryos.
[link to www.ncbi.nlm.nih.gov (secure)]