ABSTRACT
Auxiliary CaVß subunits interact with the pore forming CaVα1 subunit to promote the plasma membrane expression of high voltage-activated calcium channels and to modulate the biophysical properties of Ca2+ currents. However, the effect of CaVß subunits on channel trafficking to and from the plasma membrane is still controversial. Here, we have investigated the impact of CaVß1b and CaVß2a subunits on plasma membrane trafficking of CaV1.2 using a live-labeling strategy. We show that the CaVß1b subunit is more potent in increasing CaV1.2 expression at the plasma membrane than the CaVß2a subunit and that this effect is not related to modification of intracellular trafficking of the channel (i.e. neither forward trafficking, nor recycling, nor endocytosis). We conclude that the differential effect of CaVß subunit subtypes on CaV1.2 surface expression is likely due to their differential ability to protect CaV1.2 from degradation.
