Dynamin I phosphorylation by GSK3 controls activity-dependent bulk endocytosis of synaptic vesicles

Emma Louise Clayton (1) , Nancy Sue (1) , Karen Janet Smillie (1) , Timothy O'Leary (1) , Nicolai Bache (1) , Giselle Cheung (1) , Adam Robert Cole (1) , David J Wyllie (1) , Calum Sutherland (1) , Phillip James Robinson (1) , Michael Alan Cousin (1)

1 Centre for Integrative Physiology

Glycogen synthase kinase-3 (GSK3) is a critical enzyme in neuronal physiology, however any specific role in presynaptic function is not yet known. We show that GSK3 phosphorylates a key residue on the large GTPase dynamin I (Ser-774) both in vitro and in primary rat neuronal cultures. This is dependent on prior phosphorylation of Ser-778 by cyclin-dependent kinase 5 (cdk5). We found a specific requirement for GSK3 in activity-dependent bulk endocytosis (ADBE), but not clathrin-mediated endocytosis (CME) using both acute inhibition with pharmacological antagonists and silencing of expression using shRNA. Moreover we showed that the specific phosphorylation of Ser-774 on dynamin I by GSK3 is both necessary and sufficient for ADBE. This is the first demonstration of a presynaptic role for GSK3 and reveals that a protein kinase signalling cascade prepares synaptic vesicles (SVs) for retrieval during elevated neuronal activity.

Mots clés: Synaptic Transmission; Signal Transduction; membrane trafficking; cellular neuroscience

Emma Louise Clayton, Nancy Sue, Karen Janet Smillie, Timothy O'Leary, Nicolai Bache, et al.. Dynamin I phosphorylation by GSK3 controls activity-dependent bulk endocytosis of synaptic vesicles. Nature Neuroscience, 2010, ⟨10.1038/nn.2571⟩. ⟨hal-00543155⟩