Roles of the two Drosophila CRYPTOCHROME structural domains in circadian photoreception

• Published in: Science (American Association for the Advancement of Science) 2004-06, Vol.304 (5676), p.1503-1506
• Main Authors: Busza, A, Emery-Le, M, Rosbash, M, Emery, P
• Format: Article
• Language: English
• Subjects: animal proteins; Animals; Animals, Genetically Modified; Antibodies; binding proteins; Biochemistry. Physiology. Immunology; Biological and medical sciences; Cell Line; Circadian Rhythm; Circadian rhythms; Cryptochromes; Cysteine Endopeptidases - metabolism; Darkness; Drosophila; Drosophila melanogaster; Drosophila melanogaster - genetics; Drosophila melanogaster - physiology; Drosophila Proteins - chemistry; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Enzymes; Eye Proteins - chemistry; Eye Proteins - genetics; Eye Proteins - metabolism; Feedback (Response); Female; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Genetic aspects; Genetics; Geometric lines; Insecta; Insects; Invertebrates; Kinetics; Light; Light Signal Transduction; Luminous intensity; Male; Multienzyme Complexes - metabolism; mutants; Mutation; Neurons; Nuclear Proteins - metabolism; Period Circadian Proteins; Photoreceptor Cells, Invertebrate - chemistry; Photoreceptor Cells, Invertebrate - metabolism; Photoreceptors; Physiological aspects; Physiology. Development; Proteasome Endopeptidase Complex; Protein Binding; protein degradation; Protein Structure, Tertiary; Proteins; Receptors, G-Protein-Coupled; signal transduction; Spectral sensitivity; Yeasts
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1096973

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 (crym) 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.