IP3 dependent Ca2+ signals in muscle cells are involved in regulation of gene expression
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ENRIQUE JAIMOVICH [1] ; MARIA ANGELICA CARRASCO [1]
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[1] Universidad de Chile
Universidad de Chile
Santiago, Chile
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- Localización: Biological Research, ISSN-e 0717-6287, ISSN 0716-9760, Vol. 35, Nº. 2, 2002, págs. 195-202
- Idioma: español
- Enlaces
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Resumen
Potassium depolarization of cultured muscle cells was employed to study cellular responses linked to calcium signaling. Events occurring after depolarization include i) A transient increase of the IP3 mass (2-10s); ii) A slow calcium transient (5 to 25s) that propagates as a low concentration wave along the myotube showing a distinct calcium transient at the level of cell nuclei. Due to the presence of IP3 receptors both in the SR (A-band region) and in the nuclear envelope, these two events appear to be related; iii) Phosphorylation of mitogen activated kinases (ERK 1/2) and of the transcription factor CREB (30 s-10 min), as well as expression of the early genes c-fos, c-jun and egr-1 mRNA (5-15 min). Several independent pieces of evidence, including results obtained using inhibitors specific for individual steps, allowed us to connect these in a sequential manner. As the same type of signaling cascade can be triggered by oxidants, neurotransmitters and hormones, the ensemble of results allows us to propose a general model to describe signaling events that link membrane stimulation to regulation of gene transcription in skeletal muscle cells
