| Annotated protein: | Glycogen synthase kinase-3 beta (GSK-3 beta) (EC 2.7.11.26) (Factor A) (FA) (Serine/threonine-protein kinase GSK3B) (EC 2.7.11.1). Gene symbol: GSK3B. Taxonomy: Rattus norvegicus (Rat). Uniprot ID: P18266 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ GSK3B |
| Ontology domain: | Biological Process |
| SynGO term: | regulation of neurotransmitter receptor localization to postsynaptic specialization membrane (GO:0098696) |
| Synapse type(s): | hippocampus, glutamatergic Schaffer collateral synapse (CA3->CA1) |
| Annotated paper: | Nelson CD, et al. "Phosphorylation of threonine-19 of PSD-95 by GSK-3beta is required for PSD-95 mobilization and long-term depression" J Neurosci. 2013 Jul 17;33(29):12122-35 PMID:23864697 |
| Figure(s): | Fig 5, Fig. 6, Fig. 7D and E and Fig. 11D. |
| Annotation description: | Fig 5, Overexpression of constitutively active S9A-GSK3B reduces dendritic PSD-95 and surface GluA1 Literal: "To investigate whether GSK-3beta, which can phosphorylate T19, affects endogenous PSD-95 distribution, we transfected either wild-type GSK-3beta or constitutively active (S9A) or KD (K85M/K86I) mutants of GSK-3beta in cultured hippocampal neurons and imaged the cells 2 d later (DIV 16 +/- 2). Overexpression of constitutively active GSK-3beta -S9A caused a 35% drop in the total intensity of PSD-95 staining in dendrites (Fig. 5A,B) as well as a decrease in surface GluA1 staining by 50% compared with neighboring untransfected neurons (Fig. 5C,D). KD-GSK-3beta had no effect on dendritic PSD-95 staining intensity or surface GluA1 (Fig. 5A-D). We found that overexpressing wild-type GSK-3beta did not significantly affect PSD-95 or surface GluA1 staining (Fig. 5A,B), likely due to GSK-3beta activity being suppressed by S9 phosphorylation under basal culture conditions (Fig. 2). These data are consistent with GSK-3beta phosphorylation reducing synaptic stability of PSD-95, leading to lower levels of PSD-95 in PSDs and reduced surface AMPA receptors." Fig. 6, Overexpression of T19A-PSD-95 that that cannot be phosphorylated by GSK3B prevents S9A-GSK3B-induced loss of PSD-95 and surface GluA1. Literal "Are the effects of S9A-GSK-3beta overexpression on PSD-95 and GluA1 specifically due to phosphorylation of T19? To address this question, we tested whether the effects of S9A-GSK-3beta can be blocked by overexpression of T19A-PSD-95 (Fig. 6A,B). In control neurons transfected with WT-PSD-95-EGFP, S9A-GSK-3beta overexpression caused a slight but significant decrease of EGFP intensity in spines (20%; Fig. 6C) and a 40% reduction in surface GluA1 immunostaining (Fig. 6D). In neurons cotransfected with mutant T19A-PSD-95-EGFP, overexpression of S9AGSK-3beta had no significant effect on PSD-95 or surface GluA1 (Fig. 6C,D). This ability of the T19A mutant overexpression to protect against GSK-3beta-induced reduction of dendritic PSD-95 and surface GluA1 supports the hypothesis that the effects of GSK-3beta on PSD-95 are mainly through phosphorylation of the T19 residue." Fig. 7D and E, RNAi knockdown of GSK3B reduces NMDA-induced loss of synaptic PSD-95. Literal: "In neurons (DIV 16+/-3) transfected with GSK-3beta shRNA and beta-gal marker, there was no significant effect on mean intensity of PSD-95 staining under basal conditions, compared with luciferase shRNA-transfected control neurons. Treatment with NMDA (75 micom, 10 min) resulted in 35% reduction in mean immunofluorescence staining intensity of dendritic PSD-95 in control neurons transfected with Luciferase shRNA (Fig. 7D,E). Notably, total PSD-95 protein levels were unaffected by NMDA treatment, as assayed by Western blotting (Fig. 2A). However, in neurons transfected with GSK-3beta shRNA, the NMDA-induced reduction of dendritic PSD-95 staining intensity was significantly curtailed (Fig. 7E), indicating that GSK-3beta is required for the loss of PSD-95 from synapses following NMDA stimulation." Fig. 11D. Overexpression of PSD-95-T19A that cannot be phosphorylated by GSK3B in CA1 pyramidal neurons blocks induction of LTD. Literal: "Cultured hippocampal slices at DIV 3-5 were biolistically transfected with PSD-95, T19A-PSD-95, or T19DPSD-95, plus EGFP to mark the transfected cells. Simultaneous paired recordings of EPSCs were obtained 3 d post-transfection from neighboring untransfected and transfected CA1 pyramidal neurons.... Because GSK3-beta activity is primarily implicated in synaptic depression (Peineau et al., 2007), we examined LTD induced at Schaffer collateral-CA1 synapses by a pairing protocol. The normalized magnitude of LTD in neurons transfected with wild-type PSD-95 or PSD-95-T19D was similar to neighboring untransfected cells (50%; Fig. 11D). However, LTD induction was inhibited in cells overexpressing the mutant PSD-95-T19A, with the magnitude of depression only reaching 20%of untransfected cells (Fig. 11D). These results suggest that T19 phosphorylation of PSD-95 is necessary for the normal induction of LTD." 9/11/2017 Pim - literal: "We present evidence that phosphorylation of T19 destabilizes PSD-95 in spines, reduces membrane association of PSD-95, and is essential for AMPA receptor internalization and induction of LTD." |
| Evidence tracking, Biological System: | Intact tissue Cultured neurons |
| Evidence tracking, Protein Targeting: | RNAi / shRNA Over-expression |
| Evidence tracking, Experiment Assay: | Confocal Whole-cell patch clamp |
| Annotator(s): | Chiara Verpelli (ORCID:0000-0003-2949-9725) Carlo Sala (ORCID:0000-0003-0662-9523) |
| Lab: | CNR Neuroscience Institute Milan and Dept. of Biotechnology and Translational Medicine, University of Milan, 20129 Milan, Italy |
| SynGO annotation ID: | 1891 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |