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. 2017 Mar 23;595(10):3181–3202. doi: 10.1113/JP274015

Figure 1. CaV1.2Δ1821 is upregulated by PKA.

Figure 1

A, illustration of the setup. The oocyte was impaled with current and voltage electrodes and the injection micropipette. B and C, cAMP effects on CaV1.2. Left panels show I Ba of full‐length CaV1.2 (B) and CaV1.2Δ1821 (C) before cAMP injection (at time 1 min) and 4 min after cAMP injection, in representative cells. Insets above current traces show schematic drawings of the full‐length and truncated α1C, respectively. Lower inset in B shows the voltage step protocol. Right panels summarize the time course of cAMP effect in the same oocytes. cAMP injection is indicated by arrows. Final concentration in the oocyte was 200 μm. D, the I–V relations of CaV1.2Δ1821 in a representative cell. a, the stimulation protocol (lower panel) and the recorded currents (upper panel) before (left) and 6 min after cAMP (right) injection. The middle panel represents the sequence of currents recorded during the 6 min period following cAMP injection; the standard 20 ms voltage pulse was repeated every 10 s. b, normalized I–V curves (each point shows mean ± SEM), averaged from 5 oocytes. E, representative time course charts of I Ba, following injection of recombinant PKA‐CS, forskolin (Fsk) or water. F, representative time course charts of CFTR currents elicited by the injection of cAMP (left, 200 μm) or recombinant His‐PKA‐CS (right, 100 nm) into the oocyte. Currents were recorded at −80 mV in ND96 solution. G, summary of changes in I Ba in oocytes expressing CaV1.2Δ1821 following injection of the indicated compounds. Percentage change was calculated in each cell; number of cells tested is shown within bars. cAMP (200 μm; summary of 40 experiments); PKA‐CS (400 pm to 1 μm, 11 experiments); forskolin (100 μm, 1 experiment); Tris buffer (1 experiment); H2O (1 experiment). Statistical significance (indicated above the bars) of changes in I Ba was calculated for each treatment using paired t test. The comparison among all treatments using one‐way ANOVA showed no significant difference between groups injected with cAMP, PKA‐CS and forskolin. *** P < 0.001; ** P = 0.007; ns, not significant.