Silencing of Plasma Membrane Ca²⁺-ATPase Isoforms 2 and 3 Impairs Energy Metabolism in Differentiating PC12 Cells

Table 1

Relationship between cytosolic Ca²⁺ and ATP level. Changes in total cellular ATP level upon BAPTA treatment are expressed as % change in relation to nontreated line, in which ATP level in particular line was taken as 100%. The values of ATP concentration in steady state noninhibitory conditions are as follows: 3.66 ± 0.32, 4.72 ± 0.39, and 3.43 ± 0.66 nmol/mg for C, _2, and _3 lines, respectively, and these values are also presented in Figure 2 (conditions “+glucose”).

	C	_2	_3
Ca^2+  nM	95 ± 8	149 ± 17*	130 ± 11*
Ca^2+ + BAPTA nM	90 ± 14	100 ± 11^#	96 ± 15^#
ATP + BAPTA %	103 ± 10	80 ± 5^#	94 ± 8

< 0.05 versus control untreated cells; < 0.05 treated versus untreated cells. C: mock-transfected PC12, _2: PMCA2-reduced PC12, and _3: PMCA3-reduced PC12.