Fig. 6
From: Phosphorylation of Bok at Ser-8 blocks its ability to suppress IP3R-mediated calcium mobilization
Exogenous Bok regulates endogenous IP3R1-mediated [Ca2+]C responses in a Ser-8 phosphorylation-dependent manner in HEK-IP3R1 cells. (A) HEK-IP3R1 cells were transfected to stably express either BokWT, BokS8A, or BokS8E, with vector as a control. Lysates were probed in immunoblots as indicated, with p97 serving as a loading control. (B) [Ca2+]C (F/F0) in HEK-IP3R1 cells stably expressing the Bok constructs exposed to 100 µM CCh, added at t = 0. (C) Maximal F/F0 values (Fmax) (mean ± SEM, n = 3, ns = not significant, p > 0.05). (D) Post-maximal decline in [Ca2+]C graphed as F/Fmax. (E and F) Post-maximal area under the curve (AUC) and time to F/Fmax = 0.5 (mean ± SEM, n = 3, * and ** designates p < 0.05 and p < 0.005, respectively, ns = not significant, p > 0.05). (G) HEK-IP3R1 cells stably expressing BokWT, BokS8A, or BokS8E, with vector as a control, were exposed to 1 µM PGE1 for 2.5 min and cell lysates were probed in immunoblots for the proteins indicated, with RRXpS serving as a control for the methodology and p97 as a loading control. (H–L) Parallel analysis of cells pretreated with 1 µM PGE1 for 2.5 min prior to CCh addition (mean ± SEM, n = 3, * and ** designates p < 0.05 and p < 0.005, respectively, ns = not significant, p > 0.05)