IP3 Receptor-Dependent Cytoplasmic Ca2+ Signals Are Tightly Controlled by Cavβ3

Voltage-gated calcium channels (Cavs) are major Ca2+ entry pathways in excitable cells. Their β subunits facilitate membrane trafficking of the channel's ion-conducting α1 pore and modulate its gating properties. We report that one β subunit, β3, reduces Ca2+ release following stimulation of phospholipase C-coupled receptors and inositol 1,4,5-trisphosphate (IP3) formation. This effect requires the SH3-HOOK domain of Cavβ3, includes physical...