Regulatory subunit of L-type calcium channels ( ). Regulates the activity of L-type calcium channels that contain CACNA1A as pore-forming subunit (By similarity). Regulates the activity of L-type calcium channels that contain CACNA1C as pore-forming subunit and increases the presence of the channel complex at the cell membrane . Required for functional expression L-type calcium channels that contain CACNA1D as pore-forming subunit . Regulates the activity of L-type calcium channels that contain CACNA1B as pore-forming subunit .
Subcellular locations: Cell membrane, Sarcolemma, Cell membrane
Detected in heart ventricle (at protein level) . Isoform 1 and isoform 3 are expressed in brain, heart, spleen, central nervous system and neuroblastoma cells. Isoform 2 is expressed in skeletal muscle.