First Author | Komada M | Year | 2002 |
Journal | J Cell Biol | Volume | 156 |
Issue | 2 | Pages | 337-48 |
PubMed ID | 11807096 | Mgi Jnum | J:77228 |
Mgi Id | MGI:2181223 | Doi | 10.1083/jcb.200110003 |
Citation | Komada M, et al. (2002) [Beta]IV-spectrin regulates sodium channel clustering through ankyrin-G at axon initial segments and nodes of Ranvier. J Cell Biol 156(2):337-48 |
abstractText | beta-Spectrin and ankyrin are major components of the membrane cytoskeleton. We have generated mice carrying a null mutation in the betaIV-spectrin gene using gene trapping in embryonic stem cells. Mice homozygous for the mutation exhibit tremors and contraction of hindlimbs. betaIV-spectrin expression is mostly restricted to neurons, where it colocalizes with and binds to ankyrin-G at axon initial segments (AISs) and nodes of Ranvier (NR). In betaIV-spectrin-null neurons, neither ankyrin-G nor voltage-gated sodium channels (VGSC) are correctly clustered at these sites, suggesting that impaired action potential caused by mislocalization of VGSC leads to the phenotype. Conversely, in ankyrin-G-null neurons, betaIV-spectrin is not localized to these sites. These results indicate that betaIV-spectrin and ankyrin-G mutually stabilize the membrane protein cluster and the linked membrane cytoskeleton at AIS and NR. |