Fig. 4. Analysis of the sub-plasma membrane Ca²⁺ microdomains in HeLa overexpressing wt or E1081Q PMCA3a or3b variants.

HeLa cells were co-transfected with pmAEQ (targeted to sub-PM region) and the PMCA3 wt and E1081 mutants constructs for the two splicing variants a a, b and b c, d. Subplasmalemmal region ([Ca²⁺]_pm) was monitored after a reconstitution with coelenterazine in Ca²⁺-free KRB and and perfused in the presence of KRB/Ca²⁺ 1 mM a–c. The average peak values are shown in b–d. Bars represent means ± SEM obtained by averaging the values obtained in at least 30 independent measurements from three independent transfections for each condition. ***, p < 0.001; ****, p < 0.0001: ns not significant.