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 (By similarity). Regulatory subunit of L-type calcium channels that consist of a pore-forming alpha subunit and auxiliary beta, gamma and delta subunits. Interacts with CACNA1A, CACNA1B, CACNA1C and CACNA1S. Component of a calcium channel complex consisting of a pore-forming alpha subunit (CACNA1S) and the ancillary subunits CACNB1 or CACNB2, CACNG1 and CACNA2D1 (By similarity). Interacts with CACNA1S (PubMed:28351836). Identified in a complex with CACNA1C. Identified in a complex with the L-type calcium channel subunits CACNA1C, CACNA2D1, CACNB1 and one of the gamma subunits (CACNG4, CACNG6, CACNG7, or CACNG8) (By similarity). Part of a L-type calcium channel complex that contains CACNA1D, CACNA2D1 and CACNB1. Part of a L-type calcium channel complex that contains CACNA1B, CACNA2D1 and CACNB1 (By similarity). Interacts with JSRP1 (PubMed:16638807). Interacts with RYR1 (PubMed:21320436). Interacts with CBARP (PubMed:24751537). Detected in the inner nuclear layer in the retina (at protein level) (PubMed:21831364). Detected in skeletal muscle, brain, heart and spleen (PubMed:1385409). Belongs to the calcium channel beta subunit family.