title: Circadian and pharmacological regulation of casein kinase I in the hamster suprachiasmatic nucleus.
abstract: In mammals, the mechanism for the generation of circadian rhythms and entrainment by light-dark (LD) cycles resides in the hypothalamic suprachiasmatic nuclei (SCN), and the principal signal that adjusts this biological clock with environmental timing is the light:dark cycle. Within the SCN, rhythms are generated by a complex of molecular feedback loops that regulate the transcription of clock genes, including per and cry. Posttranslational modification plays an essential role in the regulation of biological rhythms; in particular, clock gene phosphorylation by casein kinase I , both epsilon (CKIepsilon) and delta (CKIdelta), regulates key molecular mechanisms in the circadian clock. In this paper, we report for the first time that CKI activity undergoes a significant circadian rhythm in the SCN (peaking at circadian time 12, the start of the subjective night), and its pharmacological inhibition alters photic entrainment of the clock, indicating that CKI may be a key element in this pathway.
authors.affiliation: Departamento de Ciencia y Tecnologia, Universidad Nacional de Quilmes / CONICET, Buenos Aires, Argentina.
authors.forename: Patricia V
authors.initials: PV
authors.lastname: Agostino
authors.forename: Santiago A
authors.initials: SA
authors.lastname: Plano
authors.forename: Diego A
authors.initials: DA
authors.lastname: Golombek
mesh_terms: D000818:Animals; D047389:Casein Kinase I / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology*; D006224:Cricetinae; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology*; D008027:Light; D055537:Light Signal Transduction / Q000187:drug effects / Q000502:physiology; D008297:Male; D008647:Mesocricetus; D051379:Mice; D013493:Suprachiasmatic Nucleus / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D007546:Isoquinolines; C058815:N-(2-aminoethyl)-5-chloroisoquinoline-8-sulfonamide; D047389:Casein Kinase I