Mapping organelle motion reveals a vesicular conveyor belt spatially replenishing secretory vesicles in stimulated chromaffin cells.
How neurosecretory cells spatially adjust their secretory vesicle pools to replenish those that have fused and released their hormonal content is currently unknown. Here we designed a novel set of image analyses to map the probability of tracked organelles undergoing a specific type of movement (free, caged or directed). We then applied our analysis to time-lapse z-stack confocal imaging of secretory vesicles from bovine Chromaffin cells to map the global changes in vesicle motion and directionality occurring upon secretagogue stimulation. We report a defined region abutting the cortical actin network that actively transports secretory vesicles and is dissipated by actin and microtubule depolymerizing drugs. The directionality of this "conveyor belt" towards the cell surface is activated by stimulation. Actin and microtubule networks therefore cooperatively probe the microenvironment to transport secretory vesicles to the periphery, providing a mechanism whereby cells globally adjust their vesicle pools in response to secretagogue stimulation.
Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland, Australia ; School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, Australia.
Guillaume
G
Maucort
Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland, Australia.
Ravikiran
R
Kasula
Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland, Australia.
Andreas
A
Papadopulos
School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, Australia.
Timo A
TA
Nieminen
School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, Australia.
Halina
H
Rubinsztein-Dunlop
Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland, Australia.
Frederic A
FA
Meunier
D000199:Actins / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000187:drug effects / Q000378:metabolism*; D015638:Cytochalasin D / Q000494:pharmacology; D007700:Kinetics; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology; D055503:Protein Multimerization; D022142:Secretory Vesicles / Q000378:metabolism*; D053778:Thiazolidines / Q000494:pharmacology; D059008:Time-Lapse Imaging; D050257:Tubulin Modulators / Q000494:pharmacology
D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D018722:Nicotinic Agonists; D053778:Thiazolidines; D050257:Tubulin Modulators; D015638:Cytochalasin D; D009538:Nicotine; C037067:latrunculin A