Fig. 5
From: Phosphorylation of Bok at Ser-8 blocks its ability to suppress IP3R-mediated calcium mobilization
Bok phosphorylation at Ser-8 slows the post-maximal decline in exogenous IP3R1-mediated [Ca2+]C responses in HEK-3KO cells. (A) HEK-3KO cells were transfected to express IP3R1HAWT (2 µg cDNA) and either BokWT, BokS8A, or BokS8E (0.25 µg cDNAs). Lysates were probed in immunoblots as indicated, with p97 serving as a loading control. (B) [Ca2+]C (F/F0) in transfected HEK-3KO cells exposed to 100 µM CCh, added at t = 0. Cal6 fluorescence intensity (F) was normalized to the basal (initial) F value (F0) and graphed as F/F0. (C) Maximal F/F0 values (Fmax) (mean ± SEM, n = 5, 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 = 0.6 (mean ± SEM, n = 5, * designates p < 0.05, ns = not significant, p > 0.05). (G–K) Parallel analysis of cells pretreated with 1 µM PGE1 for 2.5 min prior to CCh addition (mean ± SEM, n = 5, * designates p < 0.05, ns = not significant, p > 0.05)