There are four proteins that comprise CaVα2δ: CaVα2δ1, CaVα2δ2, CaVα2δ3 and CaVα2δ46. The CaVα2δ3 subunit is predominantly expressed in neuronal tissue. The CaVα2δ3 subunit regulates all classes of HVA calcium channels. The Caα2δ3 subunits in the nerve terminal function in synaptic morphogenesis and cytoskeletal organization, and that this role is independent of their function in α1 subunit localization and physiology.CaVα2δ3 is likely to be the primary presynaptic α2δ isoform mediating morphological development of the neuromuscular junction (NMJ), since null alleles have such a large effect on NMJ development and abolish all action-potential evoked transmission. Recent study shows that methylation-dependent transcriptional silencing of CaVα2δ3 may contribute to the metastatic phenotype of breast cancer. ATTO dyes are characterized by strong absorption (high extinction coefficient), high fluorescence quantum yield, and high photo-stability. The ATTO-594 fluorescent label belongs to the class of Rhodamine dyes and can be used with fluorescent equipment typically optimized to detect Texas Red and Alexa-594.
