Fig. 3.

Oxidation of Pin1 on Cys113 inhibits its cellular function to promote tau and APP protein turnover in neurons.

A) Pin1 Cys113 oxidation inhibits the Pin1 ability to promote tau turnover. Cells were co-transfected with tau or Flag-Pin1 or its mutants with tau and then treated with cycloheximide (100 mg/ml) in the presence or absence of H₂O₂ for the indicated times, followed by immunoblot analysis with anti-Flag, tau or tubulin antibodies, tau levels were semi-quantitated using tubulin as a loading control.

B) Cells were co-transfected with Flag-Pin1 or its mutants and then treated with cycloheximide (100 mg/ml) for the indicated times, followed by immunoblot analysis with anti-Flag, tau, cis-tau, trans-tau or tubulin antibodies.

C) Cells were co-transfected with Flag-Pin1 or its mutants with APP and then treated with cycloheximide (100 mg/ml) for the indicated times, followed by immunoblot analysis with anti-Flag, APP or tubulin antibodies. APP levels were semi-quantitated using tubulin as a loading control.

D) Cells were co-transfected with Flag-Pin1 or its mutants and then treated with cycloheximide (100 mg/ml) for the indicated times The levels of secreted Aβ 1–40 were measured by sandwich ELISA and data were normalized against the vector control. Results shown are mean ± SEM, n = 3. *, p <0.05.