scholarly journals Neurite Fasciculation Mediated by Complexes of Axonin-1 and Ng Cell Adhesion Molecule

1998 ◽  
Vol 143 (6) ◽  
pp. 1673-1690 ◽  
Author(s):  
Stefan Kunz ◽  
Marianne Spirig ◽  
Claudia Ginsburg ◽  
Andrea Buchstaller ◽  
Philipp Berger ◽  
...  

Neural cell adhesion molecules composed of immunoglobulin and fibronectin type III-like domains have been implicated in cell adhesion, neurite outgrowth, and fasciculation. Axonin-1 and Ng cell adhesion molecule (NgCAM), two molecules with predominantly axonal expression exhibit homophilic interactions across the extracellular space (axonin- 1/axonin-1 and NgCAM/NgCAM) and a heterophilic interaction (axonin-1–NgCAM) that occurs exclusively in the plane of the same membrane (cis-interaction). Using domain deletion mutants we localized the NgCAM homophilic binding in the Ig domains 1-4 whereas heterophilic binding to axonin-1 was localized in the Ig domains 2-4 and the third FnIII domain. The NgCAM–NgCAM interaction could be established simultaneously with the axonin-1–NgCAM interaction. In contrast, the axonin-1–NgCAM interaction excluded axonin-1/axonin-1 binding. These results and the examination of the coclustering of axonin-1 and NgCAM at cell contacts, suggest that intercellular contact is mediated by a symmetric axonin-12/NgCAM2 tetramer, in which homophilic NgCAM binding across the extracellular space occurs simultaneously with a cis-heterophilic interaction of axonin-1 and NgCAM. The enhanced neurite fasciculation after overexpression of NgCAM by adenoviral vectors indicates that NgCAM is the limiting component for the formation of the axonin-12/NgCAM2 complexes and, thus, neurite fasciculation in DRG neurons.

2006 ◽  
Vol 281 (47) ◽  
pp. 36052-36059 ◽  
Author(s):  
Shalu Shiv Mendiratta ◽  
Nikolina Sekulic ◽  
Francisco G. Hernandez-Guzman ◽  
Brett E. Close ◽  
Arnon Lavie ◽  
...  

2001 ◽  
Vol 154 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Charlotte F. Ratcliffe ◽  
Ruth E. Westenbroek ◽  
Rory Curtis ◽  
William A. Catterall

Sequence homology predicts that the extracellular domain of the sodium channel β1 subunit forms an immunoglobulin (Ig) fold and functions as a cell adhesion molecule. We show here that β1 subunits associate with neurofascin, a neuronal cell adhesion molecule that plays a key role in the assembly of nodes of Ranvier. The first Ig-like domain and second fibronectin type III–like domain of neurofascin mediate the interaction with the extracellular Ig-like domain of β1, confirming the proposed function of this domain as a cell adhesion molecule. β1 subunits localize to nodes of Ranvier with neurofascin in sciatic nerve axons, and β1 and neurofascin are associated as early as postnatal day 5, during the period that nodes of Ranvier are forming. This association of β1 subunit extracellular domains with neurofascin in developing axons may facilitate recruitment and concentration of sodium channel complexes at nodes of Ranvier.


2004 ◽  
Vol 77 (5) ◽  
pp. 770-770
Author(s):  
Martin V. Pedersen ◽  
Lene B. Køhler ◽  
Dorte K. Ditlevsen ◽  
Shizong Li ◽  
Vladimir Berezin ◽  
...  

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