S-adenosylmethionine reverses ilimaquinoneʹs vesiculation of the Golgi apparatus: A fluorescence study on the cellular interactions of ilimaquinone

The marine sponge metabolite ilimaquinone has a wide range of biological activities, including vesiculation of the Golgi apparatus and interference with intracellular protein trafficking. Some of these activities may arise from ilimaquinoneʹs influence on the activated methyl cycle. To visualize the morphological effects of ilimaquinone on the Golgi apparatus, NRK (normal rat kidney) cells were labeled with fluorescent wheat germ agglutinin and treated with ilimaquinone in the presence and absence of the methylating agent S-adenosylmethionine (SAMe). While ilimaquinone alone fragments the Golgi apparatus, the organelle remains intact when SAMe is included in the incubation mixture. This observation supports ilimaquinoneʹs interaction with methylation enzymes as the cause of Golgi vesiculation. The examination of a fluorescently labeled ilimaquinone analogue in NRK cells suggests that the cellular interactions of ilimaquinone are not localized to the Golgi apparatus.