Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.26 (GSK)
 6,788 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tissue-specific overexpression of the glycogen synthase kinase-3 (GSK-3) ortholog shaggy (sgg) shortens the period of the Drosophila circadian locomotor activity cycle. The short period phenotype was attributed to premature nuclear translocation of the PERIOD/TIMELESS heterodimer. Reducing SGG/GSK-3 activity lengthens period, demonstrating an intrinsic role for the kinase in circadian rhythmicity. Lowered sgg activity decreased TIMELESS phosphorylation, and it was found that GSK-3 beta specifically phosphorylates TIMELESS in vitro. Overexpression of sgg in vivo converts hypophosphorylated TIMELESS to a hyperphosphorylated protein whose electrophoretic mobility, and light and phosphatase sensitivity, are indistinguishable from the rhythmically produced hyperphosphorylated TIMELESS of wild-type flies. Our results indicate a role for SGG/GSK-3 in TIMELESS phosphorylation and in the regulated nuclear translocation of the PERIOD/TIMELESS heterodimer.
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PMID:A role for the segment polarity gene shaggy/GSK-3 in the Drosophila circadian clock. 1144 Jul 19

The Drosophila shaggy gene product is a mammalian glycogen synthase kinase-3beta (GSK-3beta) homologue that contributes to the circadian clock of the Drosophila through TIMELESS phosphorylation, and it regulates nuclear translocation of the PERIOD/TIMELESS heterodimer. We found that mammalian GSK-3beta is expressed in the suprachiasmatic nucleus and liver of mice and that GSK-3beta phosphorylation exhibits robust circadian oscillation. Rhythmic GSK-3beta phosphorylation is also observed in serum-shocked NIH3T3 cells. Exposing serum-shocked NIH3T3 cells to lithium chloride, a specific inhibitor of GSK-3beta, increases GSK-3beta phosphorylation and delays the phase of rhythmic clock gene expression. On the other hand, GSK-3beta overexpression advances the phase of clock gene expression. We also found that GSK-3beta interacts with PERIOD2 (PER2) in vitro and in vivo. Recombinant GSK-3beta can phosphorylate PER2 in vitro. GSK-3beta promotes the nuclear translocation of PER2 in COS1 cells. The present data suggest that GSK-3beta plays important roles in mammalian circadian clock.
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PMID:A role for glycogen synthase kinase-3beta in the mammalian circadian clock. 1597 22

Numerous lines of evidence suggest that a disordered circadian system contributes to the etiology and symptomatology of major psychiatric disorders. Sleep disturbances, particularly rapid eye movement (REM) sleep, have been observed in bipolar affective disorder (BPD) and schizophrenia. Therapies aimed at altering the timing and duration of sleep and realigning circadian rhythms, including sleep scheduling, wake extension, light therapy and drug therapies that alter sleep and circadian rhythms appear beneficial for affective disorders. Interventional studies aiming to correct sleep and circadian disturbances in schizophrenia are scarce, although exogenous melatonin has been shown to improve both sleep structure and psychotic symptoms. The study of molecular clock mechanisms in psychiatric disorders is also gaining interest. Genetics studies have found associations with CLOCK, PERIOD1, PERIOD3, and TIMELESS in schizophrenia. Most research on BPD has focused on polymorphisms of CLOCK, but the lithium target GSK-3 may also be significant. New research examining the role of circadian rhythms and clock genes in major mental illness is likely to produce rapid advances in circadian-based therapeutics.
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PMID:Circadian rhythms and clock genes in psychotic disorders. 2068 97