Figure 6.
Ca2+-dependent translocation of CaM into the nucleus of intact cells is not arrested by WGA. Cells were microinjected with 0.4 mg/ml fl-CaM, 2 mg/ml WGA, and 1 mg/ml 10 kDa RITC-dextran. Ratio imaging using RITC-dextran as a volume marker was used to map the relative concentration of fl-CaM in different compartments of the cell. (a) Before ionomycin treatment, the concentration of CaM in the nucleus was similar to or slightly higher than its concentration in the cytoplasm. (b) After perfusion with 1 μM ionomycin in DMEM, CaM was more concentrated in the nucleus than the cytoplasm. Comparison of a and b shows that ionomycin also induced contraction of these cells. Eight minutes elapsed between a and b.