p(HGNC:MAPT, pmod(Ph, Ser, 356))
We therefore phosphorylated full-length Tau by MARK2. The downfield chemical shift of phosphorylated residues (Fig. 4a) is in agreement with previous reports and confirms phosphorylation at S262, S293, S305, S324, S356, and S416 PubMed:29215007
3. Putative phosphorylation sites on tau protein and epitopes specific for major tau antibodies. Red color denotes amino acids phosphorylation in AD brain. PubMed:26751493
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
Acute treatment of rTg4510 mice with an O-GlcNAcase inhibitor transiently reduced tau phosphorylation at epitopes implicated in tau pathology. More importantly, long-term inhibitor treatment strongly increased tau O-GlcNAcylation, reduced the number of dystrophic neurons, and protected against the formation of pathological tau species without altering the phosphorylation of non-pathological tau. PubMed:22833681
While residues Ser-262, Ser-324, and Ser-356 were completely phosphorylated, Ser-293 in the second repeat was only 84% phosphorylated (Table 1). Furthermore, four non-KXGS phosphorylation sites were detected, two within the repeat domain (Ser-305 in R2 and Ser-352 in R4) and two more at the C-terminus (Ser-413 and Ser-416) (Figure 1B,C). Of these, Ser-305 was 66% phosphorylated and Ser-352, Ser-413, and Ser-416 were ∼45−58% phosphorylated (Table 1). Using wild-type MARK2cat at 25 °C and pH 6.8, the same phosphorylation sites were observed. The three primary sites, Ser-262, Ser-324, and Ser-356, were still completely phosphorylated. PubMed:24251416
We first confirmed that expression of an MKI-GFP fusion protein in rat hippocampal neurons effectively attenuated MARK4-mediated phosphorylation of both endogenous tau (Fig. 3A) and transfected human tau at the 12E8 sites (Fig. 3B). Phosphorylation of tau at the PHF-1 site was also reduced by MKI (Fig. 3A). It is possible that the PHF-1 site is also targeted by PAR-1/MARKs in vivo, or that the phosphorylation of tau at the 12E8 sites is a prerequisite for PHF-1 site phosphorylation, as the 12E8 sites were previously shown to be required for tau phosphorylation at other sites PubMed:22156579
Missorted dendritic MAPT showed phosphorylation mainly at the 12E8 sites upon treatment with either the autophagy inhibitor wortmannin (Fig. 4B; 57.2±9.4% dendrites) or the proteasomal inhibitor epoxomicin (Fig. 4C, 62.9±7.4% dendrites) (Fig. 4A-C, quantification in Fig. 4D), but not at the AT8 and the PHF1 (p-S396/p-S404) sites (Fig. S5, Fig 4D). PubMed:30145931
Missorted dendritic MAPT showed phosphorylation mainly at the 12E8 sites upon treatment with either the autophagy inhibitor wortmannin (Fig. 4B; 57.2±9.4% dendrites) or the proteasomal inhibitor epoxomicin (Fig. 4C, 62.9±7.4% dendrites) (Fig. 4A-C, quantification in Fig. 4D), but not at the AT8 and the PHF1 (p-S396/p-S404) sites (Fig. S5, Fig 4D). PubMed:30145931
In addition, it has been reported that in cultured neurons, Aβ oligomers induce MAPT missorting into the somatodendritic compartment, and the missorted MAPT is phosphorylated mainly at the 12E8 (p-S262/p-S356) and AT8 (p-S202/p-T205) sites [6]. PubMed:30145931
Thus, the dendritic and axonal MAPT are differentially phosphorylated. Based on this observation, we can conclude that the dendritic MAPT degraded by autophagy or proteasomal pathways is phosphorylated mainly at the 12E8 site. PubMed:30145931
Thus, the dendritic and axonal MAPT are differentially phosphorylated. Based on this observation, we can conclude that the dendritic MAPT degraded by autophagy or proteasomal pathways is phosphorylated mainly at the 12E8 site. PubMed:30145931
The NMR experiments demonstrate that MARK2- phosphorylation of Tau attenuates its binding to F-actin. Consistent with a reduced affinity, MARK2-phosphorylated Tau failed in bundling actin filaments (Fig. 4e) PubMed:29215007
The NMR experiments demonstrate that MARK2- phosphorylation of Tau attenuates its binding to F-actin. Consistent with a reduced affinity, MARK2-phosphorylated Tau failed in bundling actin filaments (Fig. 4e) PubMed:29215007
3. Putative phosphorylation sites on tau protein and epitopes specific for major tau antibodies. Red color denotes amino acids phosphorylation in AD brain. PubMed:26751493
The lysine-isoleucine-glycineserine motif (KIGS) or lysine-cysteineglycine-serine motif (KCGS) motifs in the repeat domain (S262, S293, S324, S356) can be phosphorylated by MARK, PKA, SAD kinases, CaMKII and p70S6K, which strongly reduces the tau microtubule interactions (36, 74, 96), [note that phosphorylation at these sites also inhibits tau aggregation, illustrating an analogous role for the repeat domain in the physiological and pathological functions of tau (106)]. PubMed:17493042
The lysine-isoleucine-glycineserine motif (KIGS) or lysine-cysteineglycine-serine motif (KCGS) motifs in the repeat domain (S262, S293, S324, S356) can be phosphorylated by MARK, PKA, SAD kinases, CaMKII and p70S6K, which strongly reduces the tau microtubule interactions (36, 74, 96), [note that phosphorylation at these sites also inhibits tau aggregation, illustrating an analogous role for the repeat domain in the physiological and pathological functions of tau (106)]. PubMed:17493042
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
We first confirmed that expression of an MKI-GFP fusion protein in rat hippocampal neurons effectively attenuated MARK4-mediated phosphorylation of both endogenous tau (Fig. 3A) and transfected human tau at the 12E8 sites (Fig. 3B). Phosphorylation of tau at the PHF-1 site was also reduced by MKI (Fig. 3A). It is possible that the PHF-1 site is also targeted by PAR-1/MARKs in vivo, or that the phosphorylation of tau at the 12E8 sites is a prerequisite for PHF-1 site phosphorylation, as the 12E8 sites were previously shown to be required for tau phosphorylation at other sites PubMed:22156579
Acute treatment of rTg4510 mice with an O-GlcNAcase inhibitor transiently reduced tau phosphorylation at epitopes implicated in tau pathology. More importantly, long-term inhibitor treatment strongly increased tau O-GlcNAcylation, reduced the number of dystrophic neurons, and protected against the formation of pathological tau species without altering the phosphorylation of non-pathological tau. PubMed:22833681
In addition, it has been reported that in cultured neurons, Aβ oligomers induce MAPT missorting into the somatodendritic compartment, and the missorted MAPT is phosphorylated mainly at the 12E8 (p-S262/p-S356) and AT8 (p-S202/p-T205) sites [6]. PubMed:30145931
Missorted dendritic MAPT showed phosphorylation mainly at the 12E8 sites upon treatment with either the autophagy inhibitor wortmannin (Fig. 4B; 57.2±9.4% dendrites) or the proteasomal inhibitor epoxomicin (Fig. 4C, 62.9±7.4% dendrites) (Fig. 4A-C, quantification in Fig. 4D), but not at the AT8 and the PHF1 (p-S396/p-S404) sites (Fig. S5, Fig 4D). PubMed:30145931
Missorted dendritic MAPT showed phosphorylation mainly at the 12E8 sites upon treatment with either the autophagy inhibitor wortmannin (Fig. 4B; 57.2±9.4% dendrites) or the proteasomal inhibitor epoxomicin (Fig. 4C, 62.9±7.4% dendrites) (Fig. 4A-C, quantification in Fig. 4D), but not at the AT8 and the PHF1 (p-S396/p-S404) sites (Fig. S5, Fig 4D). PubMed:30145931
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If you find BEL Commons useful in your work, please consider citing: Hoyt, C. T., Domingo-Fernández, D., & Hofmann-Apitius, M. (2018). BEL Commons: an environment for exploration and analysis of networks encoded in Biological Expression Language. Database, 2018(3), 1–11.