Caspr2, a new member of the Neurexin superfamily, is localized at the juxtaparanodes of myelinated axons and associates with K+ channels

Sebastian Poliak, Leora Gollan, Ricardo Martinez, Andrew Custer, Steven Einheber, James L. Salzer, James Trimmer, Peter Shrager, Elior Peles

Research output: Contribution to journalArticle

361 Scopus citations

Abstract

Rapid conduction in myelinated axons depends on the generation of specialized subcellular domains to which different sets of ion channels are localized. Here, we describe the identification of Caspr2, a mammalian homolog of Drosophila Neurexin IV (Nrx-IV), and show that this neurexin-like protein and the closely related molecule Caspr/Paranodin demarcate distinct subdomains in myelinated axons. While contactin-associated protein (Caspr) is present at the paranodal junctions, Caspr2 is precisely colocalized with Shaker-like K+ channels in the juxtaparanodal region. We further show that Caspr2 specifically associates with Kv1.1, Kv1.2, and their Kvβ2 subunit. This association involves the C-terminal sequence of Caspr2, which contains a putative PDZ binding site. These results suggest a role for Caspr family members in the local differentiation of the axon into distinct functional subdomains.

Original languageEnglish (US)
Pages (from-to)1037-1047
Number of pages11
JournalNeuron
Volume24
Issue number4
StatePublished - Dec 1999
Externally publishedYes

ASJC Scopus subject areas

  • Neuroscience(all)

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    Poliak, S., Gollan, L., Martinez, R., Custer, A., Einheber, S., Salzer, J. L., Trimmer, J., Shrager, P., & Peles, E. (1999). Caspr2, a new member of the Neurexin superfamily, is localized at the juxtaparanodes of myelinated axons and associates with K+ channels. Neuron, 24(4), 1037-1047.