Phosphorylation of highly conserved neurofilament medium KSP repeats is not required for myelin-dependent radial axonal growth.
J Neurosci
; 29(5): 1277-84, 2009 Feb 04.
Article
en En
| MEDLINE
| ID: mdl-19193875
ABSTRACT
Neurofilament medium (NF-M) is essential for the acquisition of normal axonal caliber in response to a myelin-dependent "outside-in" trigger for radial axonal growth. Removal of the tail domain and lysine-serine-proline (KSP) repeats of NF-M, but not neurofilament heavy, produced axons with impaired radial growth and reduced conduction velocities. These earlier findings supported myelin-dependent phosphorylation of NF-M KSP repeats as an essential component of axonal growth. As a direct test of whether phosphorylation of NF-M KSP repeats is the target for the myelin-derived signal, gene replacement has now been used to produce mice in which all serines of NF-M's KSP repeats have been replaced with phosphorylation-incompetent alanines. This substitution did not alter accumulation of the neurofilaments or their subunits. Axonal caliber and motor neuron conduction velocity of mice expressing KSP phospho-incompetent NF-M were also indistinguishable from wild-type mice. Thus, phosphorylation of NF-M KSP repeats is not an essential component for the acquisition of normal axonal caliber mediated by myelin-dependent outside-in signaling.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Serina
/
Axones
/
Prolina
/
Proteínas de Neurofilamentos
/
Secuencia Conservada
/
Secuencias Repetitivas de Aminoácido
/
Lisina
/
Vaina de Mielina
Límite:
Animals
Idioma:
En
Revista:
J Neurosci
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos