The structure of the murine calcium channel gamma-subunit gene and protein.

The gamma-subunit of voltage-gated calcium channels is a membrane protein that is associated with the skeletal muscle type of voltage gated calcium channels. Using a subunit-specific polyclonal antibody, the gamma-protein was detected in mouse skeletal muscle but not in brain, where at least five additional types of voltage-gated calcium channels are expressed. Murine genomic clones containing the full coding sequence of the gamma-subunit were isolated, the exons were mapped and sequenced. The murine gamma-subunit is encoded by a single copy gene containing 4 translated exons which are distributed over approximately 14 kilobases of DNA. The intron placement within the mouse gene correlates with the previously revealed organization of the human gamma-subunit gene, although the primary structures of the gamma-subunits are only moderately conserved between the murine, human, rat and rabbit proteins (75% identity).