Table I.
Effect of vanadate, cyclopiazonic acid, and calmodulin on active Ca2+ uptake
| Vesicle | Na Vanadate (200 μm)
|
Cyclopiazonic Acid (100 nmol mg−1 protein)
|
Calmodulin (1 μm)
|
|||
|---|---|---|---|---|---|---|
| − | + | − | + | − | + | |
| nmol mg−1 | ||||||
| Golgi | 2.6 ± 0.3 | 0.5 ± 0.05 | 2.7 ± 0.1 | 0.0 | 2.4 ± 0.1 | 2.7 ± 0.1 |
| ER | 2.9 ± 0.2 | 0.4 ± 0.1 | 3.2 ± 0.2 | 0.0 | 2.8 ± 0.1 | 6.5 ± 0.4 |
Net ATP-stimulated 45Ca2+ uptake by GA vesicles at 3 min was determined as described in “Materials and Methods.” Free Ca2+ concentration was 300 nm. Values are mean ± se of three different experiments in triplicate.