Structure and alternative splicing of the gene encoding α(1I), a human brain T calcium channel α₁ subunit

The structure of CACNA1I, the gene encoding α(1I), a human brain T Ca²⁺ channel α₁ subunit, was determined by comparison of polymerase chain reaction-amplified brain cDNA and genomic sequences. The gene consists of at least 36 exons spanning at least 115 168 basepairs of chromosome 22q12.3- 13.2. The predicted protein has 2016 amino acids and 28 potential phosphorylation sites. Alternative splicing of the gene occurs at two sites: cassette exon 9 and an alternative acceptor in exon 33. Molecular diversity generated by alternative splicing and post-translational modification of this and other members of the T α₁ subunit gene family may account for the observed heterogeneity of T currents in central neurons.