Transactivation of Trk neurotrophin receptors by G-protein-coupled receptor ligands occurs on intracellular membranes.
J Neurosci
; 24(30): 6650-8, 2004 Jul 28.
Article
en En
| MEDLINE
| ID: mdl-15282267
ABSTRACT
Neurotrophins, such as NGF and BDNF, activate Trk receptor tyrosine kinases through receptor dimerization at the cell surface followed by autophosphorylation and intracellular signaling. It has been shown that activation of Trk receptor tyrosine kinases can also occur via a G-protein-coupled receptor (GPCR) mechanism, without involvement of neurotrophins. Two GPCR ligands, adenosine and pituitary adenylate cyclase-activating polypeptide (PACAP), can activate Trk receptor activity to increase the survival of neural cells through stimulation of Akt activity. To investigate the mechanism of Trk receptor transactivation, we have examined the localization of Trk receptors in PC12 cells and primary neurons after treatment with adenosine agonists and PACAP. In contrast to neurotrophin treatment, Trk receptors were sensitive to transcriptional and translational inhibitors, and they were found predominantly in intracellular locations particularly associated with Golgi membranes. Biotinylation and immunostaining experiments confirm that most of the transactivated Trk receptors are found in intracellular membranes. These results indicate that there are alternative modes of activating Trk receptor tyrosine kinases in the absence of neurotrophin binding at the cell surface and that receptor signaling may occur and persist inside of neuronal cells.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Fenetilaminas
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Neuropéptidos
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Adenosina
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Neurotransmisores
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Receptor trkA
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Receptor trkB
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Receptores Acoplados a Proteínas G
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Aparato de Golgi
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Membranas Intracelulares
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Factores de Crecimiento Nervioso
Límite:
Animals
Idioma:
En
Revista:
J Neurosci
Año:
2004
Tipo del documento:
Article
País de afiliación:
Estados Unidos