Developing nodes of Ranvier are defined by ankyrin-G clustering and are independent of paranodal axoglial adhesion.
Journal Article (Journal Article)
Nodes of Ranvier are excitable regions of axonal membranes highly enriched in voltage-gated sodium channels that propagate action potentials. The mechanism of protein clustering at nodes has been a source of controversy. In this study, developmental analysis of nodes of Ranvier in optic nerve axons reveals that early node intermediates are defined by ankyrin-G. Other node components, including beta IV spectrin, voltage-gated sodium channels, and the L1 cell adhesion molecule neurofascin, are subsequently recruited to sites of ankyrin-G clustering. The role of intact paranodes in protein clustering was examined in the dysmyelinating mouse mutant jimpy. Jimpy mice do not have intact paranodal axoglial contacts, which is indicated by a complete lack of neurexin/contactin-associated protein/paranodin clustering in paranodes. In the absence of intact paranodes, ankyrin-G was still able to cluster, although fewer ankyrin clusters were seen in jimpy optic nerves than in wild-type optic nerves. Recruitment of Na(v)1.2, Na(v)1.6, beta IV spectrin, and neurofascin to sites of ankyrin-G clustering is unimpaired in jimpy mice, indicating that node formation occurs independent of intact paranodal axoglial contacts.
Full Text
Duke Authors
Cited Authors
- Jenkins, SM; Bennett, V
Published Date
- February 19, 2002
Published In
Volume / Issue
- 99 / 4
Start / End Page
- 2303 - 2308
PubMed ID
- 11842202
Pubmed Central ID
- PMC122360
International Standard Serial Number (ISSN)
- 0027-8424
Digital Object Identifier (DOI)
- 10.1073/pnas.042601799
Language
- eng
Conference Location
- United States