| First Author | Vullhorst D | Year | 2001 |
| Journal | Gene | Volume | 264 |
| Issue | 1 | Pages | 29-35 |
| PubMed ID | 11245975 | Mgi Jnum | J:68023 |
| Mgi Id | MGI:1931944 | Doi | 10.1016/s0378-1119(01)00327-4 |
| Citation | Vullhorst D, et al. (2001) The genomic basis of K(V)3.4 potassium channel mRNA diversity in mice. Gene 264(1):29-35 |
| abstractText | K(V)3.4 belongs to the shaw subfamily of shaker-type potassium channels. It conducts fast inactivating, high threshold currents in the central nervous system and in fast-twitch skeletal muscle fibers. The corresponding mouse gene, Kcnc4, consists of five exons spanning a region of 20 kb. Approximately 700 bp of regulatory sequence were delineated. It is GC-rich and lacks typical TATA and CAAT motifs. Instead, seven Sp-1 and three E-box elements define putative regulatory sequences. The mouse K(V)3.4 mRNA has a size of 3639 bp, 1120 bp of which are 3' untranslated region. A transcript initiated from an alternative 5'-exon was identified by RACE and verified by genomic analysis. This isoform, designated K(V)3.4d, is predominantly expressed in skeletal muscle and probably results from alternative promoter usage. It encodes a channel protein with a novel N-terminal cytoplasmic domain. It lacks the conserved sequence motifs encoding the shaw-type tetramerization domain and the 'ball' peptide, which confers fast inactivation properties. Another splice variant, K(V)3.4c, is derived by exon skipping in the C-terminal region and is expressed at similar levels in brain and muscle. These data demonstrate that differential splicing and alternative transcription start sites are utilised to generate a set of K(V)3.4 variants in skeletal muscle and brain, presumably involved in the regulation of excitability. |
