title: Constitutive activation of the ERK-MAPK pathway in the suprachiasmatic nuclei inhibits circadian resetting.
abstract: Circadian entrainment involves photic stimulation of the suprachiasmatic molecular oscillator, including activation of the ERK/MAP kinase, which is phosphorylated endogenously during the day and in response to light during the night. We aimed to disrupt the diurnal cycle of ERK phosphorylation by in vivo transfection of a constitutively active form of MEK, a MAPK kinase. This procedure did not affect normal circadian parameters, but completely inhibited light-induced phase advances. Therefore, circadian regulation of the ERK pathway is not essential for the normal mechanism of the biological clock, but it is fundamental as an interface with environmental entrainment by light.
authors.affiliation: Departamento de Ciencia y Tecnología Universidad Nacional de Quilmes/CONICET, R.S. Peña 180, (1876) Bernal Buenos Aires, Argentina.
authors.forename: Ernesto C
authors.initials: EC
authors.lastname: Hainich
authors.forename: Gastón A
authors.initials: GA
authors.lastname: Pizzio
authors.forename: Diego A
authors.initials: DA
authors.lastname: Golombek
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D006224:Cricetinae; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008297:Male; D008647:Mesocricetus / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009043:Motor Activity / Q000502:physiology; D013493:Suprachiasmatic Nucleus / Q000201:enzymology* / Q000502:physiology*; D014162:Transfection
chemical_list: D049452:Green Fluorescent Proteins; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases