Light inducesFosexpression via extracellular signal-regulated kinases 1/2 in melanopsin-expressing PC12 cells

Autor: Jakob Lerche Hansen, Birgitte Falktoft, Rikke Mortensen, Marie-Louise Bülow Moldrup, Jan Fahrenkrug, Birgitte Georg
Rok vydání: 2010
Předmět:
Zdroj: Journal of Neurochemistry. 112:797-806
ISSN: 1471-4159
0022-3042
DOI: 10.1111/j.1471-4159.2009.06504.x
Popis: J. Neurochem. (2010) 112, 797–806. Abstract The photopigment melanopsin is expressed in a subtype of mammalian ganglion cells in the retina that project to the circadian clock in the hypothalamic suprachiasmatic nucleus to mediate non-visual light information. Melanopsin renders these retinal ganglion cells intrinsically photosensitive and the cells respond to light by a membrane depolarization and induction of the immediate early response gene Fos. Previous studies showed that the light activated melanopsin-induced signaling, the phototransduction, leading to depolarization of the membrane resembles the invertebrate opsins, which involves a Gαq/11 coupled phospholipase C activation. However, the signaling proteins mediating melanopsin-induced Fos expression are unresolved. In this study, we examined the phototransduction leading to Fos expression in melanopsin-transfected PC12 cells. A pivotal role of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) was found as pharmacological blockage of this kinase suppressed the light-induced Fos expression. Illumination increased the inositol phosphate turnover and induced phosphorylation of ERK1/2 and p38 but not the c-Jun N-terminal kinase. The Gαq/11 protein inhibitor YM254890 attenuated these intracellular light responses. Our data strongly indicate that Gαq/11-mediated ERK1/2 activation is essential for expression of Fos upon illumination of melanopsin-expressing PC12 cells.
Databáze: OpenAIRE
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