Related Experiment Video
Updated: Jul 9, 2026

Measuring Synaptic Vesicle Endocytosis in Cultured Hippocampal Neurons
Published on: September 4, 2017
The dual phosphatase activity of synaptojanin1 is required for both efficient synaptic vesicle endocytosis and
Meera Mani1, Sang Yoon Lee, Louise Lucast
1Department of Biochemistry, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA.
Abstract:
Phosphoinositides have been implicated in synaptic vesicle recycling largely based on studies of enzymes that regulate phosphoinositide synthesis and hydrolysis. One such enzyme is synaptojanin1, a multifunctional protein conserved from yeast to humans, which contains two phosphoinositol phosphatase domains and a proline-rich domain. Genetic ablation of synaptojanin1 leads to pleiotropic defects in presynaptic function, including accumulation of free clathrin-coated vesicles and delayed vesicle reavailability, implicating this enzyme in postendocytic uncoating of vesicles. To further elucidate the role of synaptojanin1 at nerve terminals, we performed quantitative synaptic vesicle recycling assays in synj1(-/-) neurons. Our studies show that synaptojanin1 is also required for normal vesicle endocytosis. Defects in both endocytosis and postendocytic vesicle reavailability can be fully restored upon reintroduction of synaptojanin1. However, expression of synaptojanin1 with mutations abolishing catalytic activity of each phosphatase domain reveals that the dual action of both domains is required for normal synaptic vesicle internalization and reavailability.
More Related Videos
Related Concept Videos
Fusion of Secretory Vesicles with the Plasma Membrane
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
SNAREs and Membrane Fusion
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
The Synapse
Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Chemical Synapses
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...

