Light-induced degradation of TIMELESS and entrainment of the Drosophila circadian clock.
Two genes, period (per) and timeless (tim), are required for production of circadian rhythms in Drosophila. The proteins encoded by these genes (PER and TIM) physically interact, and the timing of their association and nuclear localization is believed to promote cycles of per and tim transcription through an autoregulatory feedback loop. Here it is shown that TIM protein may also couple this molecular pacemaker to the environment, because TIM is rapidly degraded after exposure to light. TIM accumulated rhythmically in nuclei of eyes and in pacemaker cells of the brain. The phase of these rhythms was differentially advanced or delayed by light pulses delivered at different times of day, corresponding with phase shifts induced in the behavioral rhythms.
Myers
M P
MP
Howard Hughes Medical Institute, New York, NY 10021, USA.
Wager-Smith
K
K
Rothenfluh-Hilfiker
A
A
Young
M W
MW
D000818:Animals; D001683:Biological Clocks / Q000235:genetics; D001921:Brain / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics; D003593:Cytoplasm / Q000378:metabolism; D003624:Darkness; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017344:Genes, Insect; D008027:Light; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D056950:Period Circadian Proteins; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism
D029721:Drosophila Proteins; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D011506:Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C096445:tim protein, Drosophila