The neuronal cell-adhesion molecule axonin-1 is specifically released by an endogenous glycosylphosphatidylinositol-specific phospholipase.
Eur J Biochem
; 243(1-2): 502-10, 1997 Jan 15.
Article
em En
| MEDLINE
| ID: mdl-9030778
ABSTRACT
Axonin-1, a member of the immunoglobulin/fibronectin type-III family of cell-adhesion molecules, occurs both as a glycosylphosphatidylinositol-(glycosylPtdIns)-anchored membrane-bound and a soluble form. In vivo observations show that the major part of axonin-1 is found in the soluble fraction and that soluble axonin-1 perturbs neurite fasciculation and pathfinding in the developing chicken embryo. This has prompted further investigations into the mechanism of the axonin-1 release. We demonstrate here that axonin-1 released from dorsal root ganglion neurons contains ethanolamine and inositol, components of the glycosylPtdIns anchor. Secreted axonin-1 does not exhibit the cross-reacting determinant epitope, an indication that the cleavage of the anchor is not mediated by a phosphatidylinositol-specific phospholipase C. Treatment of dorsal root ganglion neurons with 1,10-phenanthroline, an inhibitor of glycosylPtdIns-specific phospholipase D, reduces the release of axonin-1 by 56%. Moreover, glycosylPtdIns-specific phospholipase D activity was detected in dorsal root ganglion neurons and brain. These results suggest that axonin-1 is released from the membrane by an endogenously expressed glycosylPtdIns-specific phospholipase D in vivo. With domain-swaping experiments between axonin-1 and its non-released relative F11, deletion mutants and monoclonal antibodies, we demonstrate that the fourth fibronectin type-III-like domain of axonin-1 is required for the generation of the soluble form of axonin-1.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfolipase D
/
Moléculas de Adesão Celular Neuronais
Limite:
Animals
Idioma:
En
Revista:
Eur J Biochem
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
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