Actin dynamics provides membrane tension to merge fusing vesicles into the plasma membrane
Number of Authors: 20
2016 (English)In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, 12604Article in journal (Refereed) Published
Vesicle fusion is executed via formation of an Omega-shaped structure (Omega-profile), followed by closure (kiss-and-run) or merging of the Omega-profile into the plasma membrane (full fusion). Although Omega-profile closure limits release but recycles vesicles economically, Omega-profile merging facilitates release but couples to classical endocytosis for recycling. Despite its crucial role in determining exocytosis/endocytosis modes, how Omega-profile merging is mediated is poorly understood in endocrine cells and neurons containing small similar to 30-300 nm vesicles. Here, using confocal and super-resolution STED imaging, force measurements, pharmacology and gene knockout, we show that dynamic assembly of filamentous actin, involving ATP hydrolysis, N-WASP and formin, mediates Omega-profile merging by providing sufficient plasma membrane tension to shrink the Omega-profile in neuroendocrine chromaffin cells containing similar to 300 nm vesicles. Actin-directed compounds also induce Omega-profile accumulation at lamprey synaptic active zones, suggesting that actin may mediate Omega-profile merging at synapses. These results uncover molecular and biophysical mechanisms underlying Omega-profile merging.
Place, publisher, year, edition, pages
2016. Vol. 7, 12604
IdentifiersURN: urn:nbn:se:su:diva-140366DOI: 10.1038/ncomms12604ISI: 000391871100001PubMedID: 27576662OAI: oai:DiVA.org:su-140366DiVA: diva2:1086055