AAV with CAG2 promoter driven eNpHR3.0-TdTomato

This AAV expresses eNpHR3.0-TdTomato driven by an ubiquitous CAG2 promoter.

The CAG2 promoter is derived from the commonly used 1.8kb CAG/CBA (also called CAGGS) promoter. To increase the cloning capacity of size-limiting vectors using the CAG promoter, such as AAV or lentiviral vectors, CAG2 was developed by deleting a portion of about 0.6Kb of the chicken beta-actin intron from the original CAG promoter.

NpHR is a halorhodopsin or a light-sensitive chloride channel that provides silencing of neuronal activity by hyperpolarization. It offers fast inhibition, and its peak activation falls at 589 nm.

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

This ER export motif (FCYENEV) is from the vertebrate inward rectifier potassium channel Kir2.1. The motif prevents aggregate formation, decreases intracellular accumulations, and enhances tolerability at high expression levels. This is the strategy for developing many second-generation optogenetics tools