Roles of the two Drosophila CRYPTOCHROME structural domains in circadian photoreception.
CRYPTOCHROME (CRY) is the primary circadian photoreceptor in Drosophila. We show that CRY binding to TIMELESS (TIM) is light-dependent in flies and irreversibly commits TIM to proteasomal degradation. In contrast, CRY degradation is dependent on continuous light exposure, indicating that the CRY-TIM interaction is transient. A novel cry mutation (cry(m)) reveals that CRY's photolyase homology domain is sufficient for light detection and phototransduction, whereas the carboxyl-terminal domain regulates CRY stability, CRY-TIM interaction, and circadian photosensitivity. This contrasts with the function of Arabidopsis CRY domains and demonstrates that insect and plant cryptochromes use different mechanisms.
Busza
Ania
A
Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
Emery-Le
Myai
M
Rosbash
Michael
M
Emery
Patrick
P
D000818:Animals; D030801:Animals, Genetically Modified; D002460:Cell Line; D002940:Circadian Rhythm; D056931:Cryptochromes; D003546:Cysteine Endopeptidases / Q000378:metabolism; D003624:Darkness; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D005136:Eye Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005260:Female; D008027:Light; D055537:Light Signal Transduction; D008297:Male; D009097:Multienzyme Complexes / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D056950:Period Circadian Proteins; D017956:Photoreceptor Cells, Invertebrate / Q000737:chemistry* / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled
D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D009097:Multienzyme Complexes; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila; C096445:tim protein, Drosophila; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex