Fig. 6: Lsm12 is required for TPC activation by NAADP.

a Averaged traces of NAADP (1 μM in pipette solution) microinjection-induced whole-cell currents (averaged) in HEK293 WT and Lsm12-KO cells transfected with/without TPC2^L11A/L12A and Lsm12. b–d Averaged current density of NAADP microinjection-induced whole-cell TPC2 (b, c) and TPC1 (d) currents in HEK293 WT and Lsm12-KO cells. The cells (WT shown in black and Lsm12-KO in gray) were transfected with/without Lsm12 plasmid (Lsm12^Plas.) and plasmid of TPC2 WT (TPC2^WT) or plasma membrane-targeted mutant (TPC2^PM or TPC1^PM). NAADP was injected at 1 μM (b) or 100 nM (c, d). The purified Lsm12 protein (Lsm12^Pro. in c) was injected at ~100 ng/µl (~4 μM) in injection pipette solutions. Data were presented as mean value ± SEM. Unpaired Student’s t-test (two-tailed) was used to calculate p values. *, **, ***, and **** are for p values ≤ 0.05, 0.01, 0.001, and 0.0001, respectively. Inj. Solu. injection solution, Pro protein.