The cloning of double-time (dbt) is reported. DOUBLETIME protein (DBT) is most closely related to human casein kinase Iepsilon. dbtS and dbtL mutations, which alter period length of Drosophila circadian rhythms, produce single amino acid changes in conserved regions of the predicted kinase. dbtP mutants, which eliminate rhythms of per and tim expression and constitutively overproduce hypophosphorylated PER proteins, abolish most dbt expression. dbt mRNA appears to be expressed in the same cell types as are per and tim and shows no evident oscillation in wild-type heads. DBT is capable of binding to PER in vitro and in Drosophila cells, suggesting that a physical association of PER and DBT regulates PER phosphorylation and accumulation in vivo.
|Number of pages||11|
|State||Published - 1998|
- Amino Acid Sequence Animals Biological Clocks/*genetics *Casein Kinase Iepsilon Casein Kinases Conserved Sequence Drosophila/*genetics *Drosophila Proteins Gene Expression Regulation *Genes, Insect Genes, Lethal In Situ Hybridization Insect Proteins/metabolism Models, Biological Molecular Sequence Data Mutation Nuclear Proteins/metabolism Period Circadian Proteins Phosphorylation Protein Binding Protein Kinases/*genetics Sequence Homology, Amino Acid Time Factors Tissue Distribution