Fig. 3

5-HT7R domains responsible for coupling with Gs protein are not involved in interaction and activation of CDK5. A Representative confocal images of N1E-115 cells co-expressing either CDK5-eCFP and eYFP-5-HT7R mutants E325G, K327S, E325G;K327S or ΔR395. Scale bar: 10 μm. Corresponding intensity profiles are shown on the right. See also Additional file 8. B, C N1E-115 cells were co-transfected with mCherry-tagged CDK5 and HA-tagged 5-HT7R constructs as indicated, followed by IP with anti-mCherry antibody and Western blot with anti-HA antibody. Quantification of the co-IP experiments is shown below. The ratio of co-precipitated receptor was calculated, normalized to the WT sample and is presented as mean ± SD (N = 3, Kruskal–Wallis test, Dunn’s multiple comparisons, no statistical significance to WT). D, E N1E-115 cells were transfected with eGFP-Tau[R406W] mutant, together with the indicated HA-tagged 5-HT7R constructs. Phospho-Tau and total Tau levels were detected with AT270 and 5A6 antibodies, respectively. Resulting ratios (E) were normalized to GAPDH expression and are shown as normalized mean ± SD (N = 4, Kruskal–Wallis test, Dunn’s multiple comparisons, no statistical significance to WT). F The number of Tau aggregate-positive cells was counted in a confined area and is presented as a fraction of the total number of transfected cells. Data is presented as normalized mean ± SD (N = 3, n ≥ 353, Kruskal–Wallis test, Dunn’s multiple comparisons, no statistical significance to WT)