jasplakinolide and Pheochromocytoma

It has been speculated that neurosecretion can be enhanced by increasing the motion, and hence, the availability of cytoplasmic secretory vesicles. However, facilitator-induced physical mobilization of secretory vesicles has not been observed directly in living cells, and recent experimental results call this hypothesis into question. Here, high resolution green fluorescent protein (GFP)-based measurements in nerve growth factor-differentiated PC12 cells are used to test whether altering dense core vesicle (DCV) motion affects neuropeptide release. Experiments with mycalolide B and jasplakinolide demonstrate that neuropeptidergic DCV motion at the ends of processes is proportional to F-actin. Furthermore, Ba2+ increases DCV mobility without detectably modifying F-actin. Finally, we show that altering DCV motion by changing F-actin or stimulating with Ba2+ proportionally changes sustained neuropeptide release. Therefore, increasing DCV mobility facilitates prolonged neuropeptide release.

Topics: Actins; Animals; Antineoplastic Agents; Cell Differentiation; Depsipeptides; Genes, Reporter; Green Fluorescent Proteins; Luminescent Proteins; Marine Toxins; Movement; Nerve Growth Factor; Neuropeptides; Oxazoles; PC12 Cells; Peptides, Cyclic; Pheochromocytoma; Rats; Recombinant Proteins; Secretory Vesicles