The Trans Golgi Region is a Labile Intracellular Ca 2+ Store Sensitive to Emetine

The Golgi apparatus (GA) is a bona fide Ca store; however, there is a lack of GA-specific Ca mobilizing agents. Here, we report that emetine specifically releases Ca from GA in HeLa and HL-1 atrial myocytes. Additionally, it has become evident that the trans-Golgi is a labile Ca store that requires a continuous source of Ca from either the external milieu or from the ER, to enable it to produce a detectable transient increase in cytosolic Ca . Our data indicates that the emetine-sensitive Ca mobilizing mechanism is different from the two classical Ca release mechanisms, i.e. IP and ryanodine receptors. This newly discovered ability of emetine to release Ca from the GA may explain why chronic consumption of ipecac syrup has muscle side effects.