Fig. 5.

Coordinated Ca²⁺ changes in NE/ER, nucleoplasm, and cytosol of C6 and Jurkat cells. C6 (A) and Jurkat (B) cells were transfected with ER- (a) or Nu- (b) cameleon, or loaded with fura2 (c). Ratiometric imaging was carried out as in Fig. 3. Arrows marked with Ca at 550 s represent addition of CaCl₂/KCl mixture for C6 cells or CaCl₂ alone for Jurkat cells. [Ca²⁺]_ne/er was elevated in C6 cells, which express nuclear NCX, but not in Jurkat cells, which lack nuclear NCX. Each trace was average of >30 cells from 5 to 8 independent runs.