Increased internal Ca2+ mediates neural induction in the amphibian embryo.
Proc Natl Acad Sci U S A
; 91(26): 12639-43, 1994 Dec 20.
Article
en En
| MEDLINE
| ID: mdl-7809092
ABSTRACT
The molecular mechanism of neural induction is still unknown and the identity of the natural inducer remains elusive. It has been suggested that both the protein kinase C and cAMP signal transduction pathways may be involved in mediating its action. Here we provide evidence that Ca2+ is implicated in the process of transduction of the neuralizing signal. We find that an increase in intracellular Ca2+ concentration [Ca2+]i occurs during neural induction provoked in vitro by the lectin Con A in Pleurodeles waltl embryo. We demonstrate that specific L-type Ca2+ channel agonists also trigger neural induction. Conversely, noninducing lectins do not raise [Ca2+]i. Ryanodine and caffeine trigger neural induction. An increase in [Ca2+]i was also observed after treatment with the phorbol 12-myristate 13-acetate, which has been reported to be inductive. The [Ca2+]i increase triggered by phorbol ester and Con A was abolished by staurosporine and by L-type Ca2+ channel antagonists. Our findings demonstrate that the [Ca2+]i increase occurs via L-type Ca2+ channels. We suggest an amplification of this increase by a Ca(2+)-induced Ca2+ release mechanism which involves intracellular ryanodine-sensitive stores. We propose that Ca(2+)-dependent processes controlled by protein kinase C are implicated in the regulation of gene expression in response to neural induction.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Canales de Calcio
/
Calcio
/
Sistema Nervioso
Límite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
1994
Tipo del documento:
Article
País de afiliación:
Francia