Table 1.

Effect of M2, M4, and M6 mutants on ΔK_Ca

Site	Mutation	KCa	ΔKCa
			+SLN	+PLN	+SLN, +PLN
	wt	6.57  ± 0.05	−0.22  ± 0.01	−0.36  ± 0.01	−0.93  ± 0.04
M2	V89C	6.72  ± 0.04	−0.03  ± 0.01*	−0.04  ± 0.02*	ND
M4	L321A	6.33  ± 0.05	−0.10  ± 0.03*	−0.22  ± 0.01*	ND
M6	V795A	6.10  ± 0.01	−0.05  ± 0.02*	−0.03  ± 0.02*	−0.74  ± 0.01**
	L802A	6.57  ± 0.04	−0.03  ± 0.01*	−0.07  ± 0.02*	−0.19  ± 0.07**
	T805A	6.04  ± 0.04	−0.04  ± 0.01*	−0.03  ± 0.02*	−0.45  ± 0.05**
	F809A	6.24  ± 0.05	−0.07  ± 0.03*	−0.09  ± 0.04*	−0.61  ± 0.02**

The results are the mean ± SEM for three separate experiments for each mutation. ND, not determined. 

^*, P < 0.05 against wt SERCA1a expression; 

^**, P < 0.05 against triple expression of wt SERCA1a, NF-SLN, and PLN.