Structures of the murine genes for the beta1- and beta4-subunits of the voltage-dependent calcium channel.

The structures of the genomic DNA of the murine beta1- and beta4-subunits of the voltage-dependent calcium channel were mapped by comparing genomic and cDNA sequences. The gene structure analysis revealed that the murine beta1 gene consists of 15 translated exons spread over 19 kb of the genome, whereas the beta4 gene consists of 13 translated exons spread over 124 kb of the genome. Alternative spliced transcripts of the beta1 gene were also characterized. Although the total lengths differ, these subunits have exon-intron organization similar to the murine beta2- and beta3-, and human beta4-subunits, showing the highly conserved gene structure of this family. Furthermore, mRNA of these beta-subunits is strongly expressed in dorsal root ganglion neurons, which have many voltage-dependent calcium channels.