Cloning and expression of a third calcium channel beta subunit

• Published in: The Journal of biological chemistry 1993-02, Vol.268 (5), p.3450-3455
• Main Authors: Castellano, A, Wei, X, Birnbaumer, L, Perez-Reyes, E
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Blotting, Northern; Brain - physiology; Calcium Channels - genetics; Calcium Channels - physiology; Casein Kinases; Cell membranes. Ionic channels. Membrane pores; Cell structures and functions; Cloning, Molecular; DNA - genetics; DNA - isolation & purification; Female; Fundamental and applied biological sciences. Psychology; Gene Library; Heart - physiology; Kinetics; Macromolecular Substances; Male; Molecular and cellular biology; Molecular Sequence Data; Muscles - physiology; Oligodeoxyribonucleotides; Oocytes - physiology; Organ Specificity; Poly A - genetics; Poly A - isolation & purification; Polymerase Chain Reaction - methods; Protein Kinase C - genetics; Protein Kinases - genetics; Rats; RNA - genetics; RNA - isolation & purification; RNA, Messenger; Sequence Homology, Amino Acid; Xenopus
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/s0021-9258(18)53715-7

The skeletal muscle dihydropyridine receptor/Ca2+ channel consists of five distinct subunits (alpha 1, alpha 2 delta, beta 1, and gamma). Homologous alpha 1, alpha 2 delta, and beta 2 subunits are expressed in heart and brain. The present study reports the cloning and expression of a third beta subunit, beta 3, which is expressed predominantly in brain. Its open reading frame encodes a protein with 484 amino acids with a predicted molecular mass of 54,571 Da. Coexpression of beta 3 with a cardiac alpha 1 in Xenopus oocytes induces similar changes in Ca2+ channel activity as beta 1 and beta 2, that is, it increases peak currents, modulates the voltage dependence of activation, and accelerates activation. In addition, beta 3 accelerates the rate of inactivation at positive test potentials.