title: The cytoskeletal adapter protein 4.1G organizes the internodes in peripheral myelinated nerves.
abstract: Myelinating Schwann cells regulate the localization of ion channels on the surface of the axons they ensheath. This function depends on adhesion complexes that are positioned at specific membrane domains along the myelin unit. Here we show that the precise localization of internodal proteins depends on the expression of the cytoskeletal adapter protein 4.1G in Schwann cells. Deletion of 4.1G in mice resulted in aberrant distribution of both glial adhesion molecules and axonal proteins that were present along the internodes. In wild-type nerves, juxtaparanodal proteins (i.e., Kv1 channels, Caspr2, and TAG-1) were concentrated throughout the internodes in a double strand that flanked paranodal junction components (i.e., Caspr, contactin, and NF155), and apposes the inner mesaxon of the myelin sheath. In contrast, in 4.1G(-/-) mice, these proteins "piled up" at the juxtaparanodal region or aggregated along the internodes. These findings suggest that protein 4.1G contributes to the organization of the internodal axolemma by targeting and/or maintaining glial transmembrane proteins along the axoglial interface.
authors.affiliation: Department of Molecular Neurobiology and 2 Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Ivanovic
authors.forename: Ido
authors.initials: I
authors.lastname: Horresh
authors.forename: Neev
authors.initials: N
authors.lastname: Golan
authors.forename: Ivo
authors.initials: I
authors.lastname: Spiegel
authors.forename: Helena
authors.initials: H
authors.lastname: Sabanay
authors.forename: Shahar
authors.initials: S
authors.lastname: Frechter
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ohno
authors.forename: Nobuo
authors.initials: N
authors.lastname: Terada
authors.forename: Wiebke
authors.initials: W
authors.lastname: Möbius
authors.forename: Jack
authors.initials: J
authors.lastname: Rosenbluth
authors.forename: Nils
authors.initials: N
authors.lastname: Brose
authors.forename: Elior
authors.initials: E
authors.lastname: Peles
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D019556:COS Cells; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002522:Chlorocebus aethiops; D051379:Mice; D018345:Mice, Knockout; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009186:Myelin Sheath / Q000378:metabolism*; D009413:Nerve Fibers, Myelinated / Q000378:metabolism; D010525:Peripheral Nerves / Q000378:metabolism*
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; C540651:Epb4.1l2 protein, mouse; D008840:Microfilament Proteins