Regulatory subunit of L-type calcium channels (PubMed:1309651, PubMed:15615847, PubMed:8107964). 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 (PubMed:15615847). Required for functional expression L-type calcium channels that contain CACNA1D as pore-forming subunit (PubMed:1309651). Regulates the activity of L-type calcium channels that contain CACNA1B as pore-forming subunit (PubMed:8107964). {ECO:0000250|UniProtKB:P19517, ECO:0000269|PubMed:1309651, ECO:0000269|PubMed:15615847, ECO:0000269|PubMed:8107964}. This is the function of ENSG00000067191 (CACNB1, calcium voltage-gated channel auxiliary subunit beta 1).