scholarly journals Glycogen Synthase Kinase 3β Phosphorylates p21WAF1/CIP1 for Proteasomal Degradation after UV Irradiation

2007 ◽  
Vol 27 (8) ◽  
pp. 3187-3198 ◽  
Author(s):  
Ji Young Lee ◽  
Su Jin Yu ◽  
Yun Gyu Park ◽  
Joon Kim ◽  
Jeongwon Sohn
Keyword(s):  
Signaling Pathway ◽  
Uv Irradiation ◽  
Glycogen Synthase ◽  
Proteasome Inhibitors ◽  
Proteasomal Degradation ◽  
Glycogen Synthase Kinase ◽  
Target Sequence ◽  
Glycogen Synthase Kinase 3Β ◽  
P21 Protein ◽  
Gsk 3Β

ABSTRACT UV irradiation has been reported to induce p21WAF1/CIP1 protein degradation through a ubiquitin-proteasome pathway, but the underlying biochemical mechanism remains to be elucidated. Here, we show that ser-114 phosphorylation of p21 protein by glycogen synthase kinase 3β (GSK-3β) is required for its degradation in response to UV irradiation and that GSK-3β activation is a downstream event in the ATR signaling pathway triggered by UV. UV transiently increased GSK-3β activity, and this increase could be blocked by caffeine or by ATR small interfering RNA, indicating ATR-dependent activation of GSK-3β. ser-114, located within the putative GSK-3β target sequence, was phosphorylated by GSK-3β upon UV exposure. The nonphosphorylatable S114A mutant of p21 was protected from UV-induced destabilization. Degradation of p21 protein by UV irradiation was independent of p53 status and prevented by proteasome inhibitors. In contrast to the previous report, the proteasomal degradation of p21 appeared to be ubiquitination independent. These data show that GSK-3β is activated by UV irradiation through the ATR signaling pathway and phosphorylates p21 at ser-114 for its degradation by the proteasome. To our knowledge, this is the first demonstration of GSK-3β as the missing link between UV-induced ATR activation and p21 degradation.

scholarly journals DYRK1A and Glycogen Synthase Kinase 3β, a Dual-Kinase Mechanism Directing Proteasomal Degradation of CRY2 for Circadian Timekeeping

2010 ◽  
Vol 30 (7) ◽  
pp. 1757-1768 ◽  
Author(s):  
Nobuhiro Kurabayashi ◽  
Tsuyoshi Hirota ◽  
Mihoko Sakai ◽  
Kamon Sanada ◽  
Yoshitaka Fukada
Keyword(s):  
Glycogen Synthase ◽  
Circadian Variation ◽  
Proteasomal Degradation ◽  
Period Length ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3Β ◽  
Clock Gene Expression ◽  
Clock Component ◽  
Abnormal Accumulation ◽  
Gsk 3Β

ABSTRACT Circadian molecular oscillation is generated by a transcription/translation-based feedback loop in which CRY proteins play critical roles as potent inhibitors for E-box-dependent clock gene expression. Although CRY2 undergoes rhythmic phosphorylation in its C-terminal tail, structurally distinct from the CRY1 tail, little is understood about how protein kinase(s) controls the CRY2-specific phosphorylation and contributes to the molecular clockwork. Here we found that Ser557 in the C-terminal tail of CRY2 is phosphorylated by DYRK1A as a priming kinase for subsequent GSK-3β (glycogen synthase kinase 3β)-mediated phosphorylation of Ser553, which leads to proteasomal degradation of CRY2. In the mouse liver, DYRK1A kinase activity toward Ser557 of CRY2 showed circadian variation, with its peak in the accumulating phase of CRY2 protein. Knockdown of Dyrk1a caused abnormal accumulation of cytosolic CRY2, advancing the timing of a nuclear increase of CRY2, and shortened the period length of the cellular circadian rhythm. Expression of an S557A/S553A mutant of CRY2 phenocopied the effect of Dyrk1a knockdown in terms of the circadian period length of the cellular clock. DYRK1A is a novel clock component cooperating with GSK-3β and governs the Ser557 phosphorylation-triggered degradation of CRY2.

scholarly journals Dextromethorphan Attenuates NADPH Oxidase-Regulated Glycogen Synthase Kinase 3β and NF-κB Activation and Reduces Nitric Oxide Production in Group A Streptococcal Infection

2018 ◽  
Vol 62 (6) ◽  
pp. e02045-17 ◽  
Author(s):  
Chia-Ling Chen ◽  
Miao-Huei Cheng ◽  
Chih-Feng Kuo ◽  
Yi-Lin Cheng ◽  
Ming-Han Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nadph Oxidase ◽  
Nuclear Translocation ◽  
Glycogen Synthase ◽  
Glycogen Synthase Kinase ◽  
Streptococcal Toxic Shock Syndrome ◽  
Glycogen Synthase Kinase 3Β ◽  
Diphenylene Iodonium ◽  
Group A ◽  
Gsk 3Β

ABSTRACTGroup AStreptococcus(GAS) is an important human pathogen that causes a wide spectrum of diseases, including necrotizing fasciitis and streptococcal toxic shock syndrome. Dextromethorphan (DM), an antitussive drug, has been demonstrated to efficiently reduce inflammatory responses, thereby contributing to an increased survival rate of GAS-infected mice. However, the anti-inflammatory mechanisms underlying DM treatment in GAS infection remain unclear. DM is known to exert neuroprotective effects through an NADPH oxidase-dependent regulated process. In the present study, membrane translocation of NADPH oxidase subunit p47phoxand subsequent reactive oxygen species (ROS) generation induced by GAS infection were significantly inhibited via DM treatment in RAW264.7 murine macrophage cells. Further determination of proinflammatory mediators revealed that DM effectively suppressed inducible nitric oxide synthase (iNOS) expression and NO, tumor necrosis factor alpha, and interleukin-6 generation in GAS-infected RAW264.7 cells as well as in air-pouch-infiltrating cells from GAS/DM-treated mice. GAS infection caused AKT dephosphorylation, glycogen synthase kinase-3β (GSK-3β) activation, and subsequent NF-κB nuclear translocation, which were also markedly inhibited by treatment with DM and an NADPH oxidase inhibitor, diphenylene iodonium. These results suggest that DM attenuates GAS infection-induced overactive inflammation by inhibiting NADPH oxidase-mediated ROS production that leads to downregulation of the GSK-3β/NF-κB/NO signaling pathway.

scholarly journals Glycogen Synthase Kinase 3β Promotes Postoperative Cognitive Dysfunction by Inducing the M1 Polarization and Migration of Microglia

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jingjin Li ◽  
Chonglong Shi ◽  
Zhengnian Ding ◽  
Wenjie Jin
Keyword(s):  
Cognitive Dysfunction ◽  
Lithium Chloride ◽  
Glycogen Synthase ◽  
Postoperative Cognitive Dysfunction ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3Β ◽  
Central Nervous System Complication ◽  
Proinflammatory Mediators ◽  
M1 Polarization ◽  
Gsk 3Β

Postoperative cognitive dysfunction (POCD) is a common postoperative central nervous system complication, especially in the elderly. It has been consistently reported that the pathological process of this clinical syndrome is related to neuroinflammation and microglial proliferation. Glycogen synthase kinase 3β (GSK-3β) is a widely expressed kinase with distinct functions in different types of cells. The role of GSK-3β in regulating innate immune activation has been well documented, but as far as we know, its role in POCD has not been fully elucidated. Lithium chloride (LiCl) is a widely used inhibitor of GSK-3β, and it is also the main drug for the treatment of bipolar disorder. Prophylactic administration of lithium chloride (2 mM/kg) can inhibit the expression of proinflammatory mediators in the hippocampus, reduce the hippocampal expression of NF-κB, and increase both the downregulation of M1 microglial-related genes (inducible nitric oxide synthase and CD86) and upregulation of M2 microglial-related genes (IL-10 and CD206), to alleviate the cognitive impairment caused by orthopedic surgery. In vitro, LiCl reversed LPS-induced production of proinflammatory mediators and M1 polarization of microglia. To sum up these results, GSK-3β is a key contributor to POCD and a potential target of neuroprotective strategies.

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