Nonmuscle Myosin II helps regulate synaptic vesicle mobility at the Drosophila neuromuscular junction.
BACKGROUND
Although the mechanistic details of the vesicle transport process from the cell body to the nerve terminal are well described, the mechanisms underlying vesicle traffic within nerve terminal boutons is relatively unknown. The actin cytoskeleton has been implicated but exactly how actin or actin-binding proteins participate in vesicle movement is not clear.


RESULTS
In the present study we have identified Nonmuscle Myosin II as a candidate molecule important for synaptic vesicle traffic within Drosophila larval neuromuscular boutons. Nonmuscle Myosin II was found to be localized at the Drosophila larval neuromuscular junction; genetics and pharmacology combined with the time-lapse imaging technique FRAP were used to reveal a contribution of Nonmuscle Myosin II to synaptic vesicle movement. FRAP analysis showed that vesicle dynamics were highly dependent on the expression level of Nonmuscle Myosin II.


CONCLUSIONS
Our results provide evidence that Nonmuscle Myosin II is present presynaptically, is important for synaptic vesicle mobility and suggests a role for Nonmuscle Myosin II in shuttling vesicles at the Drosophila neuromuscular junction. This work begins to reveal the process by which synaptic vesicles traverse within the bouton.
Department of Biology, University of Toronto, Mississauga, ON L5L 1C6, Canada.
Sara
S
Seabrooke
Xinping
X
Qiu
Bryan A
BA
Stewart
D000818:Animals; D001370:Axonal Transport / Q000502:physiology*; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism*; D009046:Motor Neurons / Q000378:metabolism / Q000648:ultrastructure; D054792:Muscle, Striated / Q000294:innervation; D018995:Myosin Heavy Chains / Q000378:metabolism*; D009469:Neuromuscular Junction / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D013194:Staining and Labeling; D009435:Synaptic Transmission / Q000502:physiology; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D025521:Tumor Suppressor Proteins / Q000378:metabolism
D029721:Drosophila Proteins; D008565:Membrane Proteins; D025521:Tumor Suppressor Proteins; C097862:Zip protein, Drosophila; C070350:dlg1 protein, Drosophila; D018995:Myosin Heavy Chains