The PM and ER were probed using mouse anti-Na+/K+-ATPase (Upstate, Waltham, Massachusetts, United States) or rabbit anti-calnexin (Stressgen Biotechnology, Victoria, British Columbia, Canada) antibodies and the secondary antibodies, Cy3-conjugated goat anti-mouse (1:200; Jackson ImmunoResearch, West Grove, Pennsylvania, United States) or AlexaFluor 594-conjugated chicken anti-rabbit (1:200) respectively.