AAV with CAG promoter driven C1V1(E122T)-TS-Venus

This AAV expresses C1V1(E122T)-TS-Venus driven by an ubiquitous CAG promoter.

The roughly 1.8Kb CAG promoter (also known as CBA promoter or CAGGS promoter) is a strong synthetic promoter frequently used to drive high levels of gene expression in mammalian cells. The CAG promoter is composed of the following regulatory elements: (C) cytomegalovirus (CMV) early enhancer element; (A) the promoter region, the first exon, and the first intron of chicken beta-Actin gene, and (G) the splice acceptor of the rabbit beta-Globin gene. Like the EF1a promoter, the CAG promoter is commonly used as an alternative for the CMV promoter, from which the expression is decreased due to methylation/silencing. In many cell types tested, the CAG and EF1a promoters give much higher levels of expression than other commonly used cellular promoters such as the UBC and PGK promoters.

C1V1 is a chimeric channelrhodopsin made to boost membrane expression higher than VChR1 but with a different light spectrum. It is composed of ChR1 and VChR1 fragments, and implements fast, potent optical excitation at red-shifted wavelengths. C1V1(E122T) mutant has moderate off-kinetic with 130ms, and is red-shifted to 550nm, compared to C1V1.

The trafficking signal (KSRITSEGEYIPLDQIDINV) is also from the inward rectifier potassium channel Kir2.1; it serves to dramatically reduce intracellular accumulation and improve membrane targeting, leading to a profound increase of photocurrents. This is the basis for many third-generation optogenetics tools