Cloning, chromosomal location and functional expression of the human voltage-dependent calcium-channel β3 subunit


  • Note. The novel nucleotide sequence data published here have been submitted to the GenBank sequence data bank and are available under accession number L27584.

Correspondence to J. Nargeot, CRBM, CNRS, route de Mende – BP 5051, F-34033 Montpellier cedex, France


A novel human-voltage-dependent-calcium-channel (VDCC) β subunit was isolated from a 9-week-old human total-embryo cDNA library. Of the four genes encoding β-subunit isoforms that have been identified in animal species, this isoform shares strong similarity with the rat and rabbit β3-related gene product and is referred to here as Hβ3 subunit. The Hβ3 isoform is the second β subunit identified in human. Its open reading frame encodes a 482-amino-acid protein with a predicted molecular mass of 54.571 kDa. The Hβ3 mRNA is expressed mostly in brain, smooth muscle and ovary. The gene for the human Hβ3 was specifically localized on chromosome 12q13. The cloned Hβ3 subunit was further expressed in Xenopus oocytes to demonstrate its ability to modulate VDCC activity.