Circadian rhythms: in the loop at last.
The basic molecular mechanisms underlying circadian oscillators follow the same general plan across the phylogenetic spectrum: oscillating feedback loops in which clock gene products negatively regulate their own expression. The circadian clocks of animals involve at least two interacting feedback loops. This Viewpoint compares and contrasts the circadian clocks of mammals and of Drosophila, emphasizing how different players are used to create the same basic script. Both the general script and the specific details of the murine and Drosophila circadian pathways are available at Science's Signal Transduction Knowledge Environment Connections Maps.
Van Gelder
Russell N
RN
Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO 63110, USA. vangelder@vision.wustl.edu
Herzog
Erik D
ED
Schwartz
William J
WJ
Taghert
Paul H
PH
D056930:ARNTL Transcription Factors; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D001683:Biological Clocks; D056926:CLOCK Proteins; D002940:Circadian Rhythm; D056931:Cryptochromes; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D005136:Eye Proteins; D025461:Feedback, Physiological; D005420:Flavoproteins / Q000378:metabolism; D005786:Gene Expression Regulation; D008027:Light; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D056950:Period Circadian Proteins; D017956:Photoreceptor Cells, Invertebrate; D043562:Receptors, G-Protein-Coupled; D015398:Signal Transduction; D013493:Suprachiasmatic Nucleus / Q000502:physiology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D009687:Nuclear Proteins; D056950:Period Circadian Proteins; D043562:Receptors, G-Protein-Coupled; D015534:Trans-Activators; D014157:Transcription Factors; C538961:Bmal1 protein, mouse; C120526:Clk protein, Drosophila; C539040:PER protein, Drosophila; C119828:cry protein, Drosophila; C112805:cyc protein, Drosophila; C538944:Clock protein, mouse