Figure 1. Metabotropic GluR5 Links Aβo/PrPC Complexes to Fyn.
A Schematic indicating that Aβo/PrPC complexes require a co-receptor to activate Fyn in PSDs.
B Pie charts show transmembrane proteins (81) among total PSD proteins (651). Transmembrane proteins were subdivided; those that were screened in Aβo/Fyn assays (56, yellow) and those not (25, gray).
C Immunoblot of screening for Fyn activation. HEK293T cells were transfected with expression vectors for Fyn, PrPC or candidate genes. After treatment with 1 μM Aβo for 15 min, lysates were analyzed by anti-phospho-SFK (Tyr 416) or anti-Fyn immunoblot.
D The ratio of phospho-SFK to Fyn is plotted from 3 experiments with Aβo. Blue line indicates the mean of all controls. Dark gray is one standard deviation, and light gray is two standard deviations from control.
E HEK293T cells were transfected with vectors for Fyn, PrPC or mGluR5, and treated with 0 or 1 μM Aβo for 15 min. Some cultures were pre-incubated for 30 min with 100 μM MPEP prior to Aβ. Lysates were analyzed by anti-phospho-SFK (Tyr 416), anti-Fyn, anti-mGluR5, or anti-PrPC immunoblot. Actin is loading control.
F HEK293T cells were transfected with vectors for Fyn, PrPC or Myc-mGluR1 as indicated. After cell treatment with 0 or 1 μM Aβo for 15 min, lysates were analyzed by anti-phospho-SFK (Tyr 416), anti-Fyn, anti-Myc, or anti-PrPC immunoblot. Actin is loading control.
G Quantification of phospho-SFK level in lysates from E, F, normalized to Fyn. Mean±sem, n=4 experiments. **, P<0.01; *, P<0.05; ANOVA, Tukey post-hoc pairwise comparisons.
H Cortical neurons from E17 WT mice at 21 DIV were treated with 0 or 1 μM of Aβo for 15 min. Indicated samples were treated with 100 μM MTEP or 10 μM MPMQ for 30 min prior to Aβo. Lysates were subjected to immunoblot with anti-Fyn, or anti-phospho-SFK (Tyr 416). Actin is loading control.
I Cortical neurons from WT or Grm5−/− mice after 21 DIV were treated with 0 or 1 μM Aβo for 15 min. Lysates were analyzed by anti-phospho-SFK (Tyr 416), anti-Fyn, anti-mGluR5 immunoblot. Actin is loading control.
J Quantification of phospho-SFK level in lysates from H, I, normalized to Fyn. Mean±sem, n=3 experiments. ***, P<0.001; *, P<0.05; ANOVA, Tukey post-hoc pairwise comparisons.
See also Fig. S1.