Fig. S1.

IP6K1 inhibits neurotransmitter release in PC12 cells. (A–C) PC12 cells transfected with either IP6K1-WT or -KD were examined for IP6K1 expression (A) and IP₇ levels (B) by Western blotting and HPLC, respectively. Overexpression of IP6K1-WT decreased depolarization-induced [³H]-noradrenaline release (C). (D–F) PC12 cells transfected with siRNA against IP6K1 or scrambled (SCR) siRNA control were examined for IP6K1 expression (D) and IP₇ levels (E) by Western blotting and HPLC, respectively. siRNA-mediated IP6K1 knockdown increased the release of [³H]-noradrenaline (F). Error bars represent SD. ***P < 0.005; **P < 0.01; *P < 0.05 [Student’s t test (B and F), one-way ANOVA/Bonferroni posttest (C), and one-sample t test (E)].