Voltage-dependent L-type calcium channel subunit beta-3, SH3 domain (IPR035760)

Short name: CACNB3_SH3

Overlapping homologous superfamilies

Domain relationships

  • SH3 domain (IPR001452)
    • Voltage-dependent L-type calcium channel subunit beta-3, SH3 domain (IPR035760)


The beta4 subunit of voltage-dependent calcium channels (Ca(V)s) is one of four beta subunits present in vertebrates. It is highly expressed in the brain, predominantly in the cerebellum [PMID: 14500989].

Ca(V)s are multi-protein complexes that regulate the entry of calcium into cells. They impact muscle contraction, neuronal migration, hormone and neurotransmitter release, and the activation of calcium-dependent signaling pathways. They are composed of four subunits: alpha1, alpha2delta, beta, and gamma. The beta subunit is a soluble and intracellular protein that interacts with the transmembrane alpha1 subunit. It facilitates the trafficking and proper localization of the alpha1 subunit to the cellular plasma membrane [PMID: 10414294].

Vertebrates contain four different beta subunits from distinct genes (beta1-4); each exists as multiple splice variants [PMID: 9272572]. All are expressed in the brain while other tissues show more specific expression patterns. The beta subunits show similarity to MAGUK (membrane-associated guanylate kinase) proteins in that they contain SH3 and inactive guanylate kinase (GuK) domains; however, they do not appear to contain a PDZ domain [PMID: 15170217].

This entry represents the SH3 domain of the subunit beta-3.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.