Nodes of Ranvier and axon initial segments are ankyrin G–dependent domains that assemble by distinct mechanisms
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- Yulia Dzhashiashvili
- 1Department of Cell Biology,
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- Yanqing Zhang
- 1Department of Cell Biology,
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- Jolanta Galinska
- 1Department of Cell Biology,
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- Isabel Lam
- 1Department of Cell Biology,
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- Martin Grumet
- 4W.M. Keck Center for Collaborative Neuroscience and
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- James L. Salzer
- 1Department of Cell Biology,
Abstract
<jats:p>Axon initial segments (AISs) and nodes of Ranvier are sites of action potential generation and propagation, respectively. Both domains are enriched in sodium channels complexed with adhesion molecules (neurofascin [NF] 186 and NrCAM) and cytoskeletal proteins (ankyrin G and βIV spectrin). We show that the AIS and peripheral nervous system (PNS) nodes both require ankyrin G but assemble by distinct mechanisms. The AIS is intrinsically specified; it forms independent of NF186, which is targeted to this site via intracellular interactions that require ankyrin G. In contrast, NF186 is targeted to the node, and independently cleared from the internode, by interactions of its ectodomain with myelinating Schwann cells. NF186 is critical for and initiates PNS node assembly by recruiting ankyrin G, which is required for the localization of sodium channels and the entire nodal complex. Thus, initial segments assemble from the inside out driven by the intrinsic accumulation of ankyrin G, whereas PNS nodes assemble from the outside in, specified by Schwann cells, which direct the NF186-dependent recruitment of ankyrin G.</jats:p>
Journal
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- The Journal of Cell Biology
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The Journal of Cell Biology 177 (5), 857-870, 2007-06-04
Rockefeller University Press
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Details 詳細情報について
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- CRID
- 1360574093921399552
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- ISSN
- 15408140
- 00219525
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- Data Source
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- Crossref