AAV with CAG promoter driven hChR2(C128S/D156A)-EYFP

This AAV expresses hChR2(C128S/D156A)-EYFP 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.

hChR2 is a humanized version of ChR2 for mammalian expression. Wild-type ChR2, as well as a few of its mutations, provides the fastest excitation of the channelrhodopsins offered, and is widely used in in optogenetics techniques in neuroscience. hChR2(D156) mutant is another SFO mutation with a 6.9-minute open-state lifetime, and hChR2(C128S/D156A) double mutation creates a Stabilized Step Function Opsin (SSFO) with a stability of the active state up to 30 minutes.