Identification of in vitro phosphorylation sites in the growth cone protein SCG10. Effect Of phosphorylation site mutants on microtubule-destabilizing activity.

Détails

ID Serval
serval:BIB_EEA709B7695D
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Identification of in vitro phosphorylation sites in the growth cone protein SCG10. Effect Of phosphorylation site mutants on microtubule-destabilizing activity.
Périodique
Journal of Biological Chemistry
Auteur(s)
Antonsson B., Kassel D.B., Di Paolo G., Lutjens R., Riederer B.M., Grenningloh G.
ISSN
0021-9258 (Print)
ISSN-L
0021-9258
Statut éditorial
Publié
Date de publication
1998
Volume
273
Numéro
14
Pages
8439-8446
Langue
anglais
Résumé
SCG10 is a neuron-specific, membrane-associated protein that is highly concentrated in growth cones of developing neurons. Previous studies have suggested that it is a regulator of microtubule dynamics and that it may influence microtubule polymerization in growth cones. Here, we demonstrate that in vivo, SCG10 exists in both phosphorylated and unphosphorylated forms. By two-dimensional gel electrophoresis, two phosphoisoforms were detected in neonatal rat brain. Using in vitro phosphorylated recombinant protein, four phosphorylation sites were identified in the SCG10 sequence. Ser-50 and Ser-97 were the target sites for protein kinase A, Ser-62 and Ser-73 for mitogen-activated protein kinase and Ser-73 for cyclin-dependent kinase. We also show that overexpression of SCG10 induces a disruption of the microtubule network in COS-7 cells. By expressing different phosphorylation site mutants, we have dissected the roles of the individual phosphorylation sites in regulating its microtubule-destabilizing activity. We show that nonphosphorylatable mutants have increased activity, whereas mutants in which phosphorylation is mimicked by serine-to-aspartate substitutions have decreased activity. These data suggest that the microtubule-destabilizing activity of SCG10 is regulated by phosphorylation, and that SCG10 may link signal transduction of growth or guidance cues involving serine/threonine protein kinases to alterations of microtubule dynamics in the growth cone.
Mots-clé
Amino Acid Sequence, Animals, Brain/metabolism, Brain/ultrastructure, Carrier Proteins, Electrophoresis, Gel, Two-Dimensional, Membrane Proteins, Microtubules/metabolism, Microtubules/ultrastructure, Molecular Sequence Data, Mutation, Nerve Growth Factors/genetics, Nerve Growth Factors/metabolism, Phosphoproteins/genetics, Phosphoproteins/metabolism, Phosphorylation, Rats, Rats, Wistar
Pubmed
Web of science
Création de la notice
24/01/2008 15:34
Dernière modification de la notice
03/03/2018 22:33
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