p(HGNC:MAPT, pmod(Ph, Thr, 231))

Entity

Name

MAPT

Namespace

hgnc

Namespace Version

20180906

Namespace URL

https://raw.githubusercontent.com/pharmacome/terminology/b46b65c3da259b6e86026514dfececab7c22a11b/external/hgnc-names.belns

In both the detergent soluble and insoluble fractions of the brain and spinal cord homogenates of Tg Tau P301S mice, we found that tau phosphorylation was significantly reduced (T-tests, P<0.05) by the anatabine treatment for all the AD phosphorylated epitopes tested (Figure 6) DOI:10.4172/2168-975X.1000126

Interestingly, we found that tau hyperphosphorylation at Thr231 was completely blocked by the Src family tyrosine kinase inhibitor, 4-amino-5-(4- chlorophenyl)-7(t-butyl)pyrazol(3,4-d)pyramide (PP1), and by the phosphatidylinositol 3-kinase inhibitor, LY294002 (Fig. 5). PubMed:17403556

Importantly, pre-incubation of AD brain extracts with NU1 significantly blocked the increase in Thr231 phosphotau immunofluorescence (Fig. 6G), establishing the tau hyperphosphorylation was induced by Abeta oligomers in the AD brain extracts. NU1 also prevented the binding of brain-derived ADDLs to synaptic hot-spots (Fig. 6H and I). In NU1-treated cultures, the presence of large extracellular aggregates indicates that the antibody sequesters ADDLs and prevents their interactions with neurons (Fig. 6I). PubMed:17403556

Following exposure to ADDLs, double-label immunofluorescence microscopy showed high levels of tau phosphorylated at Thr231, which discriminates among AD and non-AD subjects and patients with other forms of dementia (Hampel et al., 2004, 2003), in neurons with prominent dendritic ADDL binding (detected with NU1, Fig. 2K–M). ADDL binding to synaptic hot-spots in hippocampal neurons is evident in images at highermagnification (60×objective, PanelsLand M). PubMed:17403556

Vehicle-treated neurons (Fig. 3A and E) exhibited very low phosphotau immunofluorescence, but neurons treated for 4 h with 500nM ADDLs showed significantly higher levels in immunofluorescence of P-Ser404 and P-Thr231 tau (Fig. 3B and F, respectively). Neurons treated for 4 h with 10M Abeta fibrils also showed an increase in immunofluorescence of P-Ser404 and P-Thr231 tau (Fig. 3C and G, respectively). PubMed:17403556

Verification of the findings from immunofluorescence microscopy was provided by Western blot analysis of hippocampal neuronal lysates with P404, P231 and P181 antiphosphotau antibodies. A 4 h exposure to 500nM ADDLs resulted in a significant increase in tau phosphorylated at the three epitopes, to levels similar to those observed after exposure to 10 M Abeta fibrils (Fig. 4A–D). PubMed:17403556

Vehicle-treated neurons (Fig. 3A and E) exhibited very low phosphotau immunofluorescence, but neurons treated for 4 h with 500nM ADDLs showed significantly higher levels in immunofluorescence of P-Ser404 and P-Thr231 tau (Fig. 3B and F, respectively). Neurons treated for 4 h with 10M Abeta fibrils also showed an increase in immunofluorescence of P-Ser404 and P-Thr231 tau (Fig. 3C and G, respectively). PubMed:17403556

Verification of the findings from immunofluorescence microscopy was provided by Western blot analysis of hippocampal neuronal lysates with P404, P231 and P181 antiphosphotau antibodies. A 4 h exposure to 500nM ADDLs resulted in a significant increase in tau phosphorylated at the three epitopes, to levels similar to those observed after exposure to 10 M Abeta fibrils (Fig. 4A–D). PubMed:17403556

Interestingly, we found that tau hyperphosphorylation at Thr231 was completely blocked by the Src family tyrosine kinase inhibitor, 4-amino-5-(4- chlorophenyl)-7(t-butyl)pyrazol(3,4-d)pyramide (PP1), and by the phosphatidylinositol 3-kinase inhibitor, LY294002 (Fig. 5). PubMed:17403556

Following exposure to ADDLs, double-label immunofluorescence microscopy showed high levels of tau phosphorylated at Thr231, which discriminates among AD and non-AD subjects and patients with other forms of dementia (Hampel et al., 2004, 2003), in neurons with prominent dendritic ADDL binding (detected with NU1, Fig. 2K–M). ADDL binding to synaptic hot-spots in hippocampal neurons is evident in images at highermagnification (60×objective, PanelsLand M). PubMed:17403556

AD brains could induce AD-type tau hyperphosphorylation. Consistent with the results obtained with synthetic ADDLs, we found that treatment of mature hippocampal neuronal cultures with a soluble AD brain extract led to a significant increase in P231 tau phosphorylation (Fig. 6D) compared to cultures treated with a non-AD brain extract (Fig. 6A). PubMed:17403556

Glycogen synthase 3β (GSK3β) is one of the main serine-threonine kinase responsible for tau phosphorylation and has been shown to affect tau phosphorylation at multiple AD relevant epitopes including Ser396, Ser404, Thr231 and Ser202 DOI:10.4172/2168-975X.1000126

To examine whether Pin1 affects the ability of pTau to bind microtubules, we generated pTau in vitro using purified Cdc2 (refs 17, 18), and determined its ability to bind Taxol-stabilized microtubules with or without Pin1. Although Cdc2 phosphorylation disrupted the ability of tau to bind microtubules; the binding was fully restored by preincubation with Pin1 (Fig. 5a). Furthermore, Pin1 was detected in the fraction of tau-bound microtubules (Fig. 5a). However, no Pin1 was detected in the microtubule fraction if pTau was not added (Fig. 5a), indicating that Pin1 does not bind microtubules directly. Thus, Pin1 binds pTau and restores its ability to bind microtubules. PubMed:10391244

Quantification of the Western blot showed that Cdc37 knockdown reduced phospho-Thr-231, phospho-Ser-199/Ser-202, phospho-Ser-396/Ser-404, and phospho-Ser-262/Ser-356 tau. PubMed:21367866

In contrast, no binding was observed between Pin1 and the nonphosphorylated tau (Fig. 4a), demonstrating that T231 phosphorylation is required for Pin1 binding of tau. To determine whether the WW domain of Pin1 is responsible for binding, the mutant Pin1Y23A was used, which contains a single alanine substitution at the critical Tyr 23 in theWWdomain, resulting in a loss of the phosphoserine-binding activity13. Pin1Y23A showed much less binding to pT231 peptide (Table 1). The residual binding might be due to binding of the pT231 peptide to the much lower affinity isomerase domain of Pin113. These results indicate that the WW domain mediates Pin1 binding to the pT231 sequence of tau. PubMed:10391244

This result confirms previous findings that T231 is an important Cdc2 phosphorylation site in tau, and is also consistent with Pin1 binding mitotically pTau (Fig. 1a) and being sequestered on to PHFs in AD brains, where Cdc2 is upregulated (Fig. 3). PubMed:10391244

These data suggest that tau hyperphosphorylation at Thr231, Ser262, and Ser396 by DAPK1 renders the cells more resistant to the kinase-induced apoptotic cell death, providing new insights into the tau-involved apoptotic abortion in the course of chronic neurodegeneration. PubMed:23948915

Endogenous miR-195 was knocked down using over-expression of its antisense molecule (pre-AMO-miR-195) via a lentivirus (lenti-pre-AMO-miR-195); this knockdown increased the tau phosphorylation at Ser202/Thr205, Ser262, Thr231, Ser422, and the Cdk5/p25 activation, but over-expression of miR-195 using lenti-pre-miR-195 decreased the tau phosphorylation and Cdk5/p25 activation. PubMed:26118667

Here, we found that prephosphorylation by PKA promotes GSK-3beta-catalyzed tau phosphorylation at Thr181, Ser199, Ser202, Thr205, Thr217, Thr231, Ser396 and Ser422, but inhibits its phosphorylation at Thr212 and Ser404. In contrast, the prephosphorylation had no significant effect on its subsequent phosphorylation by cdk5 at Thr181, Ser199, Thr205, Thr231 and Ser422; inhibited it at Ser202, Thr212, Thr217 and Ser404; and slightly promoted it at Ser396. PubMed:17078951

Here, we found that prephosphorylation by PKA promotes GSK-3beta-catalyzed tau phosphorylation at Thr181, Ser199, Ser202, Thr205, Thr217, Thr231, Ser396 and Ser422, but inhibits its phosphorylation at Thr212 and Ser404. In contrast, the prephosphorylation had no significant effect on its subsequent phosphorylation by cdk5 at Thr181, Ser199, Thr205, Thr231 and Ser422; inhibited it at Ser202, Thr212, Thr217 and Ser404; and slightly promoted it at Ser396. PubMed:17078951

As shown in Figure 7a, compared with the vector control, DAPK1, but not DAPK1K42A, increased the phosphorylation of exogenous tau protein in HeLa cells, as detected by Thr231-specific (AT180), Ser262-specific, and Ser396-specific (PHF-13) antibodies that recognize specific tau phosphoepitopes and/or abnormal conformations specific to AD NFT. PubMed:24853415

These data suggest that tau hyperphosphorylation at Thr231, Ser262, and Ser396 by DAPK1 renders the cells more resistant to the kinase-induced apoptotic cell death, providing new insights into the tau-involved apoptotic abortion in the course of chronic neurodegeneration. PubMed:23948915

Here, we found that prephosphorylation by PKA promotes GSK-3beta-catalyzed tau phosphorylation at Thr181, Ser199, Ser202, Thr205, Thr217, Thr231, Ser396 and Ser422, but inhibits its phosphorylation at Thr212 and Ser404. In contrast, the prephosphorylation had no significant effect on its subsequent phosphorylation by cdk5 at Thr181, Ser199, Thr205, Thr231 and Ser422; inhibited it at Ser202, Thr212, Thr217 and Ser404; and slightly promoted it at Ser396. PubMed:17078951

Pin1 binds to phosphorylated Thr231 of tau and facilitates the dephosphorylation of phosphoThr231 through isomerization (Galas et al., 2006; Hamdane et al., 2006; Lu et al., 1999a). Phosphorylation at Thr231 on tau is associated with the early events of tau aggregation and NFT (Augustinack et al., 2002). Pin1 binds and isomerizes the proline imidic peptide bond following the phosphothreonine 231 PubMed:22926167

Pin1 is indicated to facilitate Tau dephosphorylation via PP2A by binding to the phospho-Thr-231-Pro or phospho-Thr-212-Pro site PubMed:19401603

This sequence (Fig. 3G–N) is supported by Western blot analysis, phosphorylated Thr231 in three AD cases and their age-matched controls, suggesting that tau phosphorylation at Thr231 occurs before the formation of oligomers (Fig. 3O). PubMed:22253473

This is potentially physiologically significant since phosphorylation of tau at Thr-231, a target site for ERK2, GSK3β, and cdk5, occurs early in AD and can further inhibit the ability of PP2A/Bα to dephosphorylate other major AD-tau phosphoepitopes (Landrieu et al.,2011). PubMed:24653673

Following exposure to ADDLs, double-label immunofluorescence microscopy showed high levels of tau phosphorylated at Thr231, which discriminates among AD and non-AD subjects and patients with other forms of dementia (Hampel et al., 2004, 2003), in neurons with prominent dendritic ADDL binding (detected with NU1, Fig. 2K–M). ADDL binding to synaptic hot-spots in hippocampal neurons is evident in images at highermagnification (60×objective, PanelsLand M). PubMed:17403556

Quantification of the Western blot showed that Cdc37 knockdown reduced phospho-Thr-231, phospho-Ser-199/Ser-202, phospho-Ser-396/Ser-404, and phospho-Ser-262/Ser-356 tau. PubMed:21367866

In contrast, no binding was observed between Pin1 and the nonphosphorylated tau (Fig. 4a), demonstrating that T231 phosphorylation is required for Pin1 binding of tau. To determine whether the WW domain of Pin1 is responsible for binding, the mutant Pin1Y23A was used, which contains a single alanine substitution at the critical Tyr 23 in theWWdomain, resulting in a loss of the phosphoserine-binding activity13. Pin1Y23A showed much less binding to pT231 peptide (Table 1). The residual binding might be due to binding of the pT231 peptide to the much lower affinity isomerase domain of Pin113. These results indicate that the WW domain mediates Pin1 binding to the pT231 sequence of tau. PubMed:10391244

To examine whether Pin1 affects the ability of pTau to bind microtubules, we generated pTau in vitro using purified Cdc2 (refs 17, 18), and determined its ability to bind Taxol-stabilized microtubules with or without Pin1. Although Cdc2 phosphorylation disrupted the ability of tau to bind microtubules; the binding was fully restored by preincubation with Pin1 (Fig. 5a). Furthermore, Pin1 was detected in the fraction of tau-bound microtubules (Fig. 5a). However, no Pin1 was detected in the microtubule fraction if pTau was not added (Fig. 5a), indicating that Pin1 does not bind microtubules directly. Thus, Pin1 binds pTau and restores its ability to bind microtubules. PubMed:10391244

Here, we found that prephosphorylation by PKA promotes GSK-3beta-catalyzed tau phosphorylation at Thr181, Ser199, Ser202, Thr205, Thr217, Thr231, Ser396 and Ser422, but inhibits its phosphorylation at Thr212 and Ser404. In contrast, the prephosphorylation had no significant effect on its subsequent phosphorylation by cdk5 at Thr181, Ser199, Thr205, Thr231 and Ser422; inhibited it at Ser202, Thr212, Thr217 and Ser404; and slightly promoted it at Ser396. PubMed:17078951

These data suggest that tau hyperphosphorylation at Thr231, Ser262, and Ser396 by DAPK1 renders the cells more resistant to the kinase-induced apoptotic cell death, providing new insights into the tau-involved apoptotic abortion in the course of chronic neurodegeneration. PubMed:23948915

Endogenous miR-195 was knocked down using over-expression of its antisense molecule (pre-AMO-miR-195) via a lentivirus (lenti-pre-AMO-miR-195); this knockdown increased the tau phosphorylation at Ser202/Thr205, Ser262, Thr231, Ser422, and the Cdk5/p25 activation, but over-expression of miR-195 using lenti-pre-miR-195 decreased the tau phosphorylation and Cdk5/p25 activation. PubMed:26118667

This sequence (Fig. 3G–N) is supported by Western blot analysis, phosphorylated Thr231 in three AD cases and their age-matched controls, suggesting that tau phosphorylation at Thr231 occurs before the formation of oligomers (Fig. 3O). PubMed:22253473

Pin1 binds to phosphorylated Thr231 of tau and facilitates the dephosphorylation of phosphoThr231 through isomerization (Galas et al., 2006; Hamdane et al., 2006; Lu et al., 1999a). Phosphorylation at Thr231 on tau is associated with the early events of tau aggregation and NFT (Augustinack et al., 2002). Pin1 binds and isomerizes the proline imidic peptide bond following the phosphothreonine 231 PubMed:22926167

Phosphorylation of the Thr-231 residue in this motif markedly decreases the affinity of tau for PP2A. PubMed:24653673

This is potentially physiologically significant since phosphorylation of tau at Thr-231, a target site for ERK2, GSK3β, and cdk5, occurs early in AD and can further inhibit the ability of PP2A/Bα to dephosphorylate other major AD-tau phosphoepitopes (Landrieu et al.,2011). PubMed:24653673

This is potentially physiologically significant since phosphorylation of tau at Thr-231, a target site for ERK2, GSK3β, and cdk5, occurs early in AD and can further inhibit the ability of PP2A/Bα to dephosphorylate other major AD-tau phosphoepitopes (Landrieu et al.,2011). PubMed:24653673

This is potentially physiologically significant since phosphorylation of tau at Thr-231, a target site for ERK2, GSK3β, and cdk5, occurs early in AD and can further inhibit the ability of PP2A/Bα to dephosphorylate other major AD-tau phosphoepitopes (Landrieu et al.,2011). PubMed:24653673