Regulatory subunit of the voltage-gated calcium channel that gives rise to L-type calcium currents . Increases CACNA1B peak calcium current and shifts the voltage dependencies of channel activation and inactivation (By similarity). Increases CACNA1C peak calcium current and shifts the voltage dependencies of channel activation and inactivation (By similarity).
Subcellular locations: Cytoplasm
Expressed mostly in brain, colon and ovary.