Developing nodes of Ranvier are defined by ankyrin-G clustering and are independent of paranodal axoglial adhesion.
Proc Natl Acad Sci U S A
; 99(4): 2303-8, 2002 Feb 19.
Article
en En
| MEDLINE
| ID: mdl-11842202
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Nódulos de Ranvier
/
Ancirinas
Límite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2002
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos