ALTERNATIVE SPLICING CONTRIBUTES TO K+ CHANNEL DIVERSITY IN THE MAMMALIAN CENTRAL-NERVOUS-SYSTEM

In an attempt to define the molecular basis of the functional diversity of K+ channels, we have isolated overlapping rat brain cDNAs that encode a neuronal delayed rectifier K+ channel, K(v)4, that is structurally related to the Drosophila Shaw protein. Unlike previously characterized mammalian K+ channel genes, which each contain a single protein-coding exon, K(v)4 arises from alternative exon usage at a locus that also encodes another mammalian Shaw homolog, NGK2. Thus, the enormous diversity of K+ channels in mammals can be generated not just through gene duplication and divergence but also through alternative splicing of RNA.