title: Synchronization and phase-resetting by glutamate of an immortalized SCN cell line.
abstract: SCN 2.2 cultures were stably transfected with luciferase reporter constructs driven by Ca(2+)/cAMP response element, E-box, or vasoactive intestinal peptide promoter to probe the circadian properties of this clock cell line. SCN 2.2 reporter lines displayed approximately 24-h rhythms of transcriptional activation after serum-shock. Serum-shocked cultures pulsed with glutamate exhibited phase-gated induction of phospho-CREB and of VIP, CRE, and E-box promoter activity. Glutamate-induced CRE promoter activity displayed restricted sensitivity to inhibitors of nitric oxide synthase and cGMP-dependent protein kinase. The temporal pattern of these sensitivities paralleled those of the SCN to light and glutamate during the night. Taken together, our data indicate that serum-shock can synchronize the circadian clock of SCN 2.2 cells to a state consistent with the day/night transition and, thus, establishes a temporal context for this cell line.
authors.affiliation: Departments of Cell and Structural Biology, University of Illinois at Urbana-Champaign, 601 South Goodwin Avenue, Urbana, IL 61801, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Hurst
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: Mitchell
authors.forename: Martha U
authors.initials: MU
authors.lastname: Gillette
mesh_terms: D001683:Biological Clocks; D002460:Cell Line; D002940:Circadian Rhythm; D003470:Culture Media / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D018698:Glutamic Acid / Q000494:pharmacology*; D015640:Ion Channel Gating; D008027:Light; D008156:Luciferases / Q000235:genetics; D011401:Promoter Regions, Genetic; D020218:Response Elements; D015398:Signal Transduction; D013493:Suprachiasmatic Nucleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D014660:Vasoactive Intestinal Peptide
chemical_list: D003470:Culture Media; D017362:Cyclic AMP Response Element-Binding Protein; D014660:Vasoactive Intestinal Peptide; D018698:Glutamic Acid; D008156:Luciferases