title: Juxtaparanodal clustering of Shaker-like K+ channels in myelinated axons depends on Caspr2 and TAG-1.
abstract: In myelinated axons, K+ channels are concealed under the myelin sheath in the juxtaparanodal region, where they are associated with Caspr2, a member of the neurexin superfamily. Deletion of Caspr2 in mice by gene targeting revealed that it is required to maintain K+ channels at this location. Furthermore, we show that the localization of Caspr2 and clustering of K+ channels at the juxtaparanodal region depends on the presence of TAG-1, an immunoglobulin-like cell adhesion molecule that binds Caspr2. These results demonstrate that Caspr2 and TAG-1 form a scaffold that is necessary to maintain K+ channels at the juxtaparanodal region, suggesting that axon-glia interactions mediated by these proteins allow myelinating glial cells to organize ion channels in the underlying axonal membrane.
authors.affiliation: Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Poliak
authors.forename: Daniela
authors.initials: D
authors.lastname: Salomon
authors.forename: Hadas
authors.initials: H
authors.lastname: Elhanany
authors.forename: Helena
authors.initials: H
authors.lastname: Sabanay
authors.forename: Brent
authors.initials: B
authors.lastname: Kiernan
authors.forename: Larysa
authors.initials: L
authors.lastname: Pevny
authors.forename: Colin L
authors.initials: CL
authors.lastname: Stewart
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Xu
authors.forename: Shing-Yan
authors.initials: SY
authors.lastname: Chiu
authors.forename: Peter
authors.initials: P
authors.lastname: Shrager
authors.forename: Andrew J W
authors.initials: AJ
authors.lastname: Furley
authors.forename: Elior
authors.initials: E
authors.lastname: Peles
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000648:ultrastructure; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D002450:Cell Communication / Q000235:genetics; D058969:Contactin 2; D018390:Gene Targeting; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D008854:Microscopy, Electron; D009154:Mutation / Q000235:genetics; D009413:Nerve Fibers, Myelinated / Q000378:metabolism* / Q000648:ultrastructure; D009419:Nerve Tissue Proteins / Q000172:deficiency* / Q000235:genetics; D009431:Neural Conduction / Q000235:genetics; D009457:Neuroglia / Q000378:metabolism / Q000648:ultrastructure; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D011901:Ranvier's Nodes / Q000378:metabolism* / Q000648:ultrastructure; D051637:Shaker Superfamily of Potassium Channels
chemical_list: C548674:CNTN2 protein, human; C403049:CNTNAP2 protein, human; D015816:Cell Adhesion Molecules, Neuronal; C548675:Cntn2 protein, mouse; D058969:Contactin 2; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D015221:Potassium Channels; D051637:Shaker Superfamily of Potassium Channels