Voltage-dependent calcium channels (VDCCs) are large (>400 kDa) heteromers which contain, minimally, three core subunits 1, 2/ , in a 1:1:1 stoichiometry1. Expression of VDCC gene products in Xenopus oocytes, or transfected cells shows that the 1 subunits contain the ion channel pore while the auxiliary 2/ and subunits confer optimal cell surface expression and channel kinetics1. Until recently, the only exception to the above paradigm was the skeletal muscle VDCC, which, in addition to the 1, 2/ , core motif, also has an additional tightly associated integral membrane glycoprotein subunit termed 1. Upon co-expression with the 1.1, 2/ 1, 1a subunits of the skeletal muscle VDCC, subunits alter the peak currents, and the kinetics of channel activation and inactivation with the overall effect being a normalisation of currents to those resembling the endogenous channel2. Together, these results suggest that subunits modulate skeletal muscle VDCCs by stabilising their conformation. _x000B_The 2 subunits, or stargazin, the product of a gene mutated in the stargazer mouse, is a homolog of the 1 channel and is selectively expressed in the brain. It is considered to be a putative neuronal Ca2+ channel subtype mainly based on its homology to the 1.
We accept Visa and MasterCard in our online store.
We can get your purchases to you wherever you are.
As an Axol customer you have access to our support team and product specialists.