Constitutively active protein kinase that acts as a negative regulator in the hormonal control of glucose homeostasis, Wnt signaling and regulation of transcription factors and microtubules, by phosphorylating and inactivating glycogen synthase (
GYS1 or
GYS2), EIF2B,
CTNNB1/beta-catenin,
APC,
AXIN1,
DPYSL2/CRMP2,
JUN,
NFATC1/NFATC,
MAPT/TAU and
MACF1. Requires primed phosphorylation of the majority of its substrates. In skeletal muscle, contributes to insulin regulation of glycogen synthesis by phosphorylating and inhibiting
GYS1 activity and hence glycogen synthesis. May also mediate the development of insulin resistance by regulating activation of transcription factors. Regulates protein synthesis by controlling the activity of initiation factor 2B (EIF2BE/
EIF2B5) in the same manner as glycogen synthase. In Wnt signaling,
GSK3B forms a multimeric complex with
APC,
AXIN1 and
CTNNB1/beta-catenin and phosphorylates the N-terminus of
CTNNB1 leading to its degradation mediated by ubiquitin/proteasomes. Phosphorylates
JUN at sites proximal to its DNA-binding domain, thereby reducing its affinity for DNA. Phosphorylates
NFATC1/NFATC on conserved serine residues promoting
NFATC1/NFATC nuclear export, shutting off
NFATC1/NFATC gene regulation, and thereby opposing the action of calcineurin. Phosphorylates
MAPT/TAU on 'Thr-548', decreasing significantly
MAPT/TAU ability to bind and stabilize microtubules.
MAPT/TAU is the principal component of neurofibrillary tangles in Alzheimer disease. Plays an important role in
ERBB2-dependent stabilization of microtubules at the cell cortex. Phosphorylates
MACF1, inhibiting its binding to microtubules which is critical for its role in bulge stem cell migration and skin wound repair. Probably regulates NF-kappa-B (
NFKB1) at the transcriptional level and is required for the NF-kappa-B-mediated anti-apoptotic response to
TNF-alpha (
TNF/
TNFA). Negatively regulates replication in pancreatic beta-cells, resulting in apoptosis, loss of beta-cells and diabetes. Through phosphorylation of the anti-apoptotic protein
MCL1, may control cell apoptosis in response to growth factors deprivation. Phosphorylates
MUC1 in breast cancer cells, decreasing the interaction of
MUC1 with
CTNNB1/beta-catenin. Is necessary for the establishment of neuronal polarity and axon outgrowth. Phosphorylates
MARK2, leading to inhibit its activity. Phosphorylates
SIK1 at 'Thr-182', leading to sustain its activity. Phosphorylates
ZC3HAV1 which enhances its antiviral activity. Phosphorylates
SNAI1, leading to its
BTRC-triggered ubiquitination and proteasomal degradation. Phosphorylates
SFPQ at 'Thr-687' upon T-cell activation. Phosphorylates
NR1D1 st 'Ser-55' and 'Ser-59' and stabilizes it by protecting it from proteasomal degradation. Regulates the circadian clock via phosphorylation of the major clock components including
ARNTL/BMAL1,
CLOCK and
PER2 (PubMed:19946213, PubMed:28903391). Phosphorylates
CLOCK AT 'Ser-427' and targets it for proteasomal degradation (PubMed:19946213). Phosphorylates
ARNTL/BMAL1 at 'Ser-17' and 'Ser-21' and primes it for ubiquitination and proteasomal degradation (PubMed:28903391). Phosphorylates
OGT at 'Ser-3' or 'Ser-4' which positively regulates its activity. Phosphorylates
MYCN in neuroblastoma cells which may promote its degradation (PubMed:24391509). Regulates the circadian rhythmicity of hippocampal long-term potentiation and
ARNTL/BMLA1 and
PER2 expression (By similarity). Acts as a regulator of autophagy by mediating phosphorylation of
KAT5/TIP60 under starvation conditions, leading to activate
KAT5/TIP60 acetyltransferase activity and promote acetylation of key autophagy regulators, such as
ULK1 and
RUBCNL/Pacer (PubMed:30704899). Negatively regulates extrinsic apoptotic signaling pathway via death domain receptors. Promotes the formation of an anti-apoptotic complex, made of
DDX3X, BRIC2 and
GSK3B, at death receptors, including
TNFRSF10B. The anti-apoptotic function is most effective with weak apoptotic signals and can be overcome by stronger stimulation (PubMed:18846110).
UniProt