Fig. 2: TYK2 phosphorylates tau at Tyr29 residue and thus stabilizes tau protein.
From: TYK2 regulates tau levels, phosphorylation and aggregation in a tauopathy mouse model
a,b, IB image of the phosphorylation of tau at Tyr residues in the presence (a) or absence (b) of TYK2 in HEK293T cells. Tau protein was collected by IP and detected by pan-phospho-Tyr antibody. p-Tyr was observed only in the presence of TYK2 and was lost in the phosphorylation disabling mutation at Tyr29 (tau441-Y29F) indicated by loss of p-Tyr signal despite the addition of TYK2. c, Schematic diagram of Tyr residues of tau441 protein. d, IB image of p-Tyr signal detected in neither tau441-Y29F nor tau treated with tau intrabody masking Tyr29 on tau protein in HEK293T cells. Either tau441 or tau441-Y29F was co-expressed with TYK2 in HEK293T cells that stably expressed either tau intrabody (clone HJ8.5, targeting tau amino acid residues 25–30) or control intrabody (clone HJ15.4). e,f, IB image of ptau detected by our ptau (pY29) antibody (e) or ptau (pY18) antibody (f) in the indicated samples in the presence or absence of tau intrabody. g–j, IB images and quantification of tau showing the turnover rate of tau441 (g and i) and tau441-Y29F (h and j; n = 6, n is the number of biological repeats). Mouse primary cultured cortical neurons were virally infected with genes encoding tau441 WT or tau441-Y29F under a TTA-inducible promoter. Tau protein was expressed by DOX treatment for 24 h, after which DOX was removed and cells were collected at indicated time points. The blots are representative of three independent experiments. **P < 0.005, ***P < 0.0005 versus vector-expressing control. Data presented as mean ± s.e.m., two-way ANOVA/Dunnett’s test. 5-F, tau with all five Tyr converted to Phe.
